The Vehicle Construction System: Level based

[BlackJaw]

I've done draft 1 of all chapters other then the last. aside from some things that came up while working on latter chapters (which need to be tweaked in the earlier chapters... like a meta-magic feat for casting spells on big vehicles) most of the work is done... aside from the complicated and key chapter of vehicle creation.

The orginal concept I was working on was point based and based off all the fun I had making space ships in alternity. Nifty yes, but also very complicated. too complicated. It worked in Alternity but thats because alternity was a point buy system for characters... so building ships was like building characters.

To that end maybe building a vehicle in the cosmonomicon rules should be like building a character in D&D... pick a vehicle "race" like Construct (most ships you can think of), Plant (elf living plant ships), and maybe Abberation, undead, vermin... etc. then you need to add levels in classes up to the vehicle's HD. classes represent the focus of limited ship system space and design ideals... so they are Engines, Armor, Weapons, and Support. Thus a 12 HD vehicle (which would be something around a Huge vehicle... good size for a fighter or other personal craft) might look something like this: Huge sized Vehicle (construct) Engines 5/Armor 2/Weapons 3/Support 2.

Levels in those classes provide special functions (weapon mounts, faster speed, more manuvering, or special functions something like feats, etc)

Ok so here is the run down as I'm working on it (off and on I admit):

Ship building step by step:

Step one: How big of a ship do you want?
A ship's size determines what the ship can do. really big engines and guns don't fit in a smaller vehicle, and you can't put one of everything into medium sized vehicles no matter how much money you throw at it. Similarly it's easy to destory a smaller vehicle with a fireball or two, but a mothership can put up a fireball or forty before it goes down.
Basicaly for each size category of vehicle there is a Hit Dice range. If you want to make a flying sky cycle, you'll be using a large vehicle (for humans anyways) while a gnome could ride a medium sized one. On the other hand a flying aircraft carrier would be much larger... colossal I or larger, with a lot more hitdice.
Now each size group not only has a range of hit dice to pick from (you pay a base price per hit dice, so you may not be able to afford the max hitdice for your size).
Also, the Hit Dice is your ship's "character level." For each hit dice it has you will need to pick a "class" from the list, giving your vehicle extra weapons, or thicker armor plate, or better (bigger) engines, or special features/systems. thus larger vehicles have more hit dice/hit points and they have more systems because you can fit more systems in them... but you are paying for all of it. Weapons and special support systems will cost extra as well... levels of weapon let you but weapons into a vehilce but doesn't cover the cost of the weapon itself. various special systems also cost money depending on the system. everything else is covered in teh cost of hte hitdice.

Step Two: What kind of vehicle is it? What is it made out of?
If you were building a character, this is the step where you pick the race. For vehicle, most will be Construct. Space shuttles, biplanes, coastal cutters with magic sails, etc. They are all objects. They are all constructs.
Contruct would be the most common type in most games I can think of. It is also more then just a construct, like a gollem or sheild guardian. it's an object, meaning it has a hardness and takes damage diffrently then objects. The price per Hitdice of a Construct vehicle has a lot to do with what it is made of. Wood vehicles have hardness like wood and are not that expensive. Adamantine vehicles have much better hardness and cost a lot more. A list will be needed. All the SRD fantasy materials would be included, pluss some options that you may not be thinking of. Bone, ice, glass, crystal, etc... just because I can think of them beign used.
BUT construct is not the only option. You could also make some living (and unliving ships).
A Plant type ship is a living ship made by either growing them spicificaly, or by using magic to shape them from living trees/etc. This best fits elves. Plant ships are living, so they heal naturaly with rest, and can be healed with cure spells while a construct ship would need to be repaired (or use repair spells).
Aberation type are for more organic living ships. Anyone seen farscape? Like a Plant vehicle it heal and be healed. it is, however, not as great an option because it is not immune to death effects... it is a creature. You can critical it, cast slay living at it, etc. It may have an inteligence, but a pilot can still fly it (making it a living vehicle, not a creature-vessel that you ride). The key is it still needs a pilot to fly... the minor inteligence of the vehicle just regulates the vehicle. anyways living ships have the benefit of being targetable by any spell with a traget of creature... making them easier to enhance with magic then constructs. They also have a constitution score giving them bonus hit points that plants and consturcts don't get... of course they can also be poisoned, sneak attacked, critical hit, etc...
Undead type vehicles are very uncommon. your more likely to use a construct [bone] then use the extream amounts of necromatic negative energy needed to animate a ship-sized corpse... but if done you have something similar to a living ship. healed by inflict spells, a nice hit die (d12) and immune to criticals and other nasty effects. An undead vehicle still needs a pilot and is not inteligent... turning it doesn't make it fly away (turning the pilot would) but it would likely have some sort of penalty to piloting skill checks. if you turn it well enough to destory it, well you destroy it. rebuking it would inflict +2 bonus to piloting checks if the rebuker wants it to fly well... otherwise its a -2 to piloting. commanding it makes it a -4 or +4 but doesn't destory it.
I'm not sure about the vermin type... but it's an idea... drow spider ships is the only reason I'm thinking about it. Insects and similar creatures (aracnids, slugs, snails, etc) would be great base creatures for altering (genetics, magic, both) into ships... especialy for nasty critters like beholders, mindflayers, etc. still those might be best done as aberation types at that point... so vermin isn't likely needed.

Race/type also determines the type of Hit dice for each level the vehicle has... undead are d12, constructs are d10, etc. I might change this later so that hit dice are based on level... I need to look at it later.

Step Three: Pick class levels for the vehicle.
So now that we have a type, size, and hit dice... we need levels.
For each and every hit dice the vehicle has, it also needs a level from one of the following: Engine, Weapons, Armor, Support.
A level provides a Fort save bonus for the vehicle (even objects make for saves sometimes). it also provides some other features. Depending on what class is taken, you get weapon slots, and special features, and various other bonuses... lets list those shall we:
Armor bonus
Natural Armor bonus
Fort save (maybe to borrow a page from CBoEM and make it a single save for all?)
Weapon slots (weapon class gets these every level or ever other... other classes get them less often)
Special System (something like a feat... but its a device or add-on that provides any number of misc funcitons or bonuses... its like a feat in that diffrent functions/systems have prerequisiets and can only be taken once unless otherwise state... one preqre is cost too. Suppor levels give these every level or every other level).
Speed points or bonuses of some kind.
Manuvering points or bonuses of some kind.
Hover/min-speed points or bonuses of some kind.

Of those last three I'm thinking that each level of engine lets you add a lot to one and a little to the others, or maybe all to one and none to the others.

Now a vehicle has a low base speed and manuverability for its size (slow and clumsy) but with each level of engine you get bonuses to that so eventualy you can be more manuverable and faster with levels... although it takes more levels for larger crafts.

Multi-classing is encouraged. Think d20 Modern base classes... for vehicles.

Step Four: Pick & buy special systems.
This is like picking feats for a character. Special systems are additional systems you can add to a vehicle. life support, passenger or crew space, magical systems... etc. A list will be needed for this part, including my previous notes on Magical systems that function like magic items... cloaking is invisibility spells, etc. Minor armor bonuses, speed bonuses, manuvering bonuses, Blimp systems... etc This is a list of options, and this is where things shine. Example ideas: Advanced Power Core = 5 charges of power a round. some systems or weapons need charges to work. You can take this more then once. without it, you'd have no charges for things like energy guns, or force sheild systems... etc.
Running list:
Speed boost (only once, all others by class)
Manuvering boost (only once, all others by class)
Gun port: one medium (only once, all others by class)
Extra Armor: +2 (only once, all others by class)
Save boost: +2 (only once)
Force Sheild: gives a sheild bonus based off charges spent. only need it once.
Generator: gives 5 charges around, can be taken more then once for +5 more charges.
Crew Space: gives some internal crew space/rooms. Total square footage based off ship size. Take it more then once for more rooms.
Blimp/Derigable: The vehicle effectively becomes one size larger without gaining more hitdice or levels... but it can hover and it's cheap.
Cargo Space: similar to crew space but it's cargo area
Non-Dimensional space: this can be used as cargo or crew space... but its magicaly enhanced area (bigger inside then on the outside like a bag of holding). it's expensive but gives a flat set of extra space... which is closed off in non-magic enviroments so it has its dangers.
Extra Fuel: depedning on your setting, a vehicle may be in danger of running out of fuel after a while (how long depends on settings) but taking this adds 100% to base time span. you can take it more then once.
Magical System: the mechanic for adding magic effects or spell effects to a vehicle through crafting charged items combined with the vehicle meta-magic feat. (which I will write up and post later)
cockpit: without it you ride the ship exposed like on a motor cyclye or WW1 aircraft. taking this once provides internal space for 1-2 people depending on vehicle size.
Deck: Requires cockpit. it is an enclosed space where you can fit multiple people and stations... thus you could have more then one co-pilot, allowing others to spend their actions using ship systems or aiding you.
Lifesupport: requires at least 1 crew space or cockpit? provides a stabalized system inside the vehicle protecting people inside from external conditions (like vacuume exposure). taking it once supports X number of medium creatures... taking it more oftne increases the number of creaturs supported.
Gravity generator: provides gravity, requires life support and 1 charge a round?

Step Five: Pick & buy weapons.
Each weapon slot a vehicle has lets you get 1 medium vehicle weapon... another list to make. Now having 20 ranks of weapons lets you have 20 medium weapons... think about those pirate ships of old with 20 cannons packed onto the decks. On the other hand you could use weapon slots to get bigger weapons. 2 slots becomes a large weapon slot. 3 huge weapon... etc. You can have weapons up to once size larger then the vehicle... but those are slots, not weapons. you buy weapons to put in those slots from the list.
Now I'll build a list of basic things... balistas, catapults, cannons of old, etc. I'll also make a mechanic for building energy weapons & modern-future projectile weapons. Energy weapons use charges... extra costs can increase rate of fire or maybe make it masterwork +1 to attack. Projectile weapons are the same system but do normal weapon damage types instead of energy types, and they use ammo instead of charges... machine gun vs plasma cannon. in both cases bigger ones do more damage. You can get them made magical using normal magic weapon creation rules. Balistas/etc are the cheapest but they take a lot longer to reload.

Step Six detials.
What sort of layout does it have, what does it look like, what's the name and history... the fun part. If it has internal spaces you may want to get some furnishings... etc. Want a library for your wizard? well if you got a spare room go right ahead... same with magic labs, curches, brigs... just buy locks and the like... or even use things from the non-OGC Stronghold builder's guide... to much can be done here to list in this book so we won't try. This isn't a "home base building" project afterall.

So what do you think?
Does this system work? does it make sense? is it flexible enough? do you think it will be to easy to unbalance? is it simplified enough (the other point buy type option was really nast in the simplicity and balancing areas, and would fill SO MANY PAGES with lists of components to pick from.) I think this system will work better.

 

[Turanil]

Many cool ideas indeed...

I did not read toroughly. Yet several ideas seem cool. My comments and suggestions :

- The type of the ship/vehicule is excellent. When it comes to starships it will enable to make really alien starships (plant-like, undead, etc.).

- I don't know if it brings something to have levels, but it looks cool I don't know why. My main wish is that PCs must have a way of customizing, improving their vehicle. Levels could be the trick, but has it to rely on experience points ? Maybe rather on money, the more you add to the ship (the more levels it gets), the more costly it becomes. Also, money is not the only answer, some feats or skills ranks should be necessary, and failing a Craft check or something could wield potential results in the future.

- Hit-dice, hit-points. Well, I have my own preferences. I don't like when hit-points and die of damage are different whether creatures or ships are concerned. As such, a laser cannon should do (for example) 8d6 of damage both on creatures and ships alike. Then, the ship should have a huge amount of hit-points (maybe when taking levels, instead of d6, d8, etc. have d60, d80 meaning d6 x 10, etc.). However this is the whole number of hit-points. For a starship there MUST BE a location system. For example, you can locally pierce the hull in making, say, just 25 points of damage. The ship is not destroyed, just damaged there, with relevant effects.

- Now, what about the size of the ship, and the levels (difference between a starfighter, and an imperial star destroyer ?). I think levels should have nothing to do with ship's size.

 

[Turanil]

Just another idea...

- Hit-dice, hit-points. Well, I have my own preferences. I don't like when hit-points and die of damage are different whether creatures or ships are concerned. As such, a laser cannon should do (for example) 8d6 of damage both on creatures and ships alike. Then, the ship should have a huge amount of hit-points (maybe when taking levels, instead of d6, d8, etc. have d60, d80 meaning d6 x 10, etc.).

I have two further ideas :
- Ship's hit-points total. A level only provide a d4, d6, d8, d10, or d12 as normally. However (!!!) you then multiply by the vehicle's size. For example, say the smallest vehicle is an airbike: multiply factor is 1. Then multiply factor are x5, x10, x50, x100, x200, x500, x1000 (don't be shy for values!). As such, an enormous starship like an imperial cruiser would get d8 x 1000 hit-oints for example. But this is the total amount of hit-points; you can pierce the hull with a much lesser number of dmg pts, but the whole ship is just slightly damaged.

- Laser canons. Rolling 8d6 of damage each round can be quickly tedious. However, say there is shield giving damage reduction of 2d4 die of damage. So, first round roll 2d4=5, the laser only does 3d6 of damage (that must bypass hardness also). Second round roll 2d4=3, the laser does 5d6 of damage. Then, hull is a certain amount of hit-points here. Say 4d8 since it is 4th level with a d8 char. class. Yet, the ship being an imperial star-destroyer has a whole total of 4d8 x 1000, meaning with that single hole, it is not much damaged.

 

[BlackJaw]

I did not read toroughly

That might explain some of the issues your having with it (that it's a new concept for me so it's now worked out all the way yet). Also, you are not apperently familiar with the other chapters of the Cosmo that are already done and more or less set, which includes dealing with combat and its effects, and dealing with vehicles, vessels, and flying creatures in a way that will let them interact with each other equaly. We are not trying to make a new combat system... the main idea is to extend the current D&D rules to air/etc medium. the only thing we reworked was manuvering rules (those in teh DMG are so complicated and annoying to use) and we did so in a way that applies to all flying objects, effectively replacing it all instead of just making a new set for just vehicles.

I don't know if it brings something to have levels, but it looks cool I don't know why. My main wish is that PCs must have a way of customizing, improving their vehicle. Levels could be the trick, but has it to rely on experience points ? Maybe rather on money, the more you add to the ship (the more levels it gets), the more costly it becomes. Also, money is not the only answer, some feats or skills ranks should be necessary, and failing a Craft check or something could wield potential results in the future.

Again, levels and classes are terms I'm looking to replace so that it doesn't conjure images of a 20 level system for characters of the same size, with XP requirements and a value of use in combat or other purposes attached to higher levels rather then lower levels. I have always intended it to be a cost (money/gp) system as this is more or less equipment. Also there is no leveling up of vehicles... they are built at a set number of hitdice. You could later rebuild them or work on them (customize them) by changing levels or features (costing money again) but you can't level them up.

I don't like when hit-points and die of damage are different whether creatures or ships are concerned.

I have no idea what you are taking about. The system I posted has a vehicle weapons... these are weapons on vehicles, but they do the same amount of damage to anyone/thing you shoot at. Now there is a note in there that objects don't take damage like creatures do, but that generaly doesn't apply to vehicle weapons (well those that don't do energy damage) because they are effectievly siege weapons... that is all basicaly covered in the D&D PHB. I also mentioned that you can alter the stats of a weapon by spending more to increase rate of fire or damage type... or by spending more and devoting more hull space to it and getting bigger weapons. A Large longsword in D&D 3.5 does more damage then a medium sized one... same concept. A large laser gun does more damage then a medium one.

Then, the ship should have a huge amount of hit-points (maybe when taking levels, instead of d6, d8, etc. have d60, d80 meaning d6 x 10, etc.). However this is the whole number of hit-points.

You see I'm indicating a much larger number of hit dice (levels is still a wrong term as it has other concepts incorrectly attached to it). I intend to have hit dice in the hundreads... so a stardestroy sized craft would have say maybe 128d10 (704 hp good enough for you?) Maybe more... I'd have to know what size it is... and i haven't yet made (or found... maybe i made already) the Hit Dice to size chart. Again, it is a range for each size, and the larger ones have large ranges.

For a starship there MUST BE a location system. For example, you can locally pierce the hull in making, say, just 25 points of damage. The ship is not destroyed, just damaged there, with relevant effects.

A system for coveirng all of this has been done already in the combat chapters already made. that said, most systems on a vehicle can not be targeted any more then you can aim for the head on person in D&D. Now you can do things like sunder attacks, etc in D&D and similar things are being designed for this extention of that system... but to much work along these lines (like being able to attack 5' or 10' sections of a vehicle seperatly) makes for extreamly annoying combat mechanics, and slows combat down very fast.

- Now, what about the size of the ship, and the levels (difference between a starfighter, and an imperial star destroyer ?). I think levels should have nothing to do with ship's size.

We have size systems already made. You know that small, medium, large, huge, garg, colossal system that D&D uses? same system. We have extended another few Colossal sizes for those mother ships (Star destroyer vs super star destroyer) but otherwise its the same system.
Again: your looking at levels as a value descriptor. I mean hit dice as a way to cap the capibilities of a vehicel. As you post elsewhere, there isn't a ferrari that is off-road, holds 5 people, and has other special features in one small light package. By connecting hit dice and vehicle systems you get a way to cap how much you can fit in a vehicle... and as that concept goes it has every reason to be connected to vehicle size.

Ship's hit-points total. A level only provide a d4, d6, d8, d10, or d12 as normally. However (!!!) you then multiply by the vehicle's size. For example, say the smallest vehicle is an airbike: multiply factor is 1. Then multiply factor are x5, x10, x50, x100, x200, x500, x1000 (don't be shy for values!). As such, an enormous starship like an imperial cruiser would get d8 x 1000 hit-oints for example. But this is the total amount of hit-points; you can pierce the hull with a much lesser number of dmg pts, but the whole ship is just slightly damaged.

these is no hit point multiplication system anywhere else in core D&D/d20. I don't think it would be espeicaly useful to make one up. Considering how many hit dice we are talking about for the larger crafts, I think its also not really needed.

Laser canons. Rolling 8d6 of damage each round can be quickly tedious. However, say there is shield giving damage reduction of 2d4 die of damage. So, first round roll 2d4=5, the laser only does 3d6 of damage (that must bypass hardness also). Second round roll 2d4=3, the laser does 5d6 of damage. Then, hull is a certain amount of hit-points here. Say 4d8 since it is 4th level with a d8 char. class. Yet, the ship being an imperial star-destroyer has a whole total of 4d8 x 1000, meaning with that single hole, it is not much damaged.

Most vehicles are objects and thus have a hardness based on their size. also, your looking at a good sized laser cannon for 8d6 damage! your more likely to see 1, 2, or 3 d6 damage unless its a good sized craft, in which case it should have such high dice values. for such a powerful gun. A dice ignoring DR system is also something odd and not found in D&D yet. We are trying to keep this similar to core rules so that it works with everything else out there (fantasy vehicle vs dragon for example). Again, making rules for localizing hull breaches, etc is a hard thing. I'd be more tempted to attach such effects to a critical hit system but any other way of doing it is just needless complication of combat.

 

[Turanil]

All of this is so complicated...

I am interested in all this subject, because I am preparing a sci-fi campaign. Creating new races and classes, compiling OGC skills, feats and monsters, describing worlds and cultures, all of this is pretty simple. However, I got a headhache trying to understand all these starship combat and construction work, comparing the different d20 games I bought on these subjects and not finding what I want...

I will wait to see what the result of this Cosmonimicon work.

 

[BlackJaw]

Ok, so the first step in detailing this system will be to define the inherent properties of each type of vehicle. Note that i would like to keep them all more or less equal to each other although pricing will be the more useful and needed way of balencing. mostly we need to look at the inherent abilities/etc that go with each type:

first let's define some subtypes: Object, and Vehicle. Object simply gives something all the benefits of being an object as defined in the rPHB, something animated objects from the rMM more or less have. The vehicle subtype might allow just about anything to be flown at some point or another, but also is useful for other game purposes, as it can be attached to something making it "technicaly" a vehicle.

Object: The object sub type gives the following benefits:
Objects have a hardness as determined by their primary material. (which will each need seperate costs. hardness found on rPHB p166). All damage is subject to hardness unless otherwise noted.
Acid and Sonic damage do full damage and ignore hardness.
Electricty and fire attacks deal half damage before aplyng hardness.
Cold damage does one quarter damage before aplying hardness.
Ranged weapons, other then seige weapons, do half damage before hardness.
Immune to critical hits, & nonlethal damage.
Considered and Object, not a creature, so immune to spells that have a target of Creature.

Vehicle: This subtype denotes a "creature" that is made or modified for flight controled by a pilot not the creature itself. Vehicles make will saves on their own if not immune, although remember that flight control is based on the pilot, not the vehicle. They also make fort saves on their own. Pilots make Reflex saves for their vehicles, modified by the vehicle's size modifier. Generaly this descriptor should not be attached to true creatures, as it is intended for applying only to "shells & hulls" latter filled with gear for controling and other special systems. As a guide, if you want to blend creatures and vehicle systems/etc then you would not want to apply any benefits of the Monster's hit dice or levels (like bab, saves, feats, etc) to those which also provide vehicle emphasis. If the vehicle has an inteligence score, it may get skill points for each hit dice it has. Most vehicles have effective Inteligence, scores of "-".

Aberration [vehicle]:
This is the better way to define living ships, as they rarerly fit other creature definitions. Living ships are generaly made or grown with no inteligence score (like vermin) although it is possible to make, or more likely grow, one with some inteligence. Regardless, these vehicles are always made with set of direct controls allowing a pilot to fly them like any other craft. It the vehicle lacks these direct controls, it is a creature used for a mount rather then a vehicle.
d8 + con modifier Hit points.
Good will save (although the mindcontrolling a vehicle is often not effective).
Aberrations eat, sleep, and breathe.
Aberration vehicles start with base ability scores of 10 before being modified for size above or bellow medium using the chart on page 291 rMM. The exception is the Inteligence score which has a starting score of "-".
These abberation vehicles are Mindless.

Construct [object][vehicle]:
Constructs with the "new" object sub-type.
These are basicaly objects, like planes, jets, and hot air balloons.
As constructs they also get the benefits of the construct type:
d10 hit dice
no good saving throws (a fort save may be needed for vehicles from time to time)
No CON score (some vehicles are alive and have con scores)
Immunity to all mind-affecting effects.
Immunity to poison, sleep, paralysis, stunning, disease, death effects, and necromancey effects.
Cannot heal damage on their own, but can benefit from repair.
Not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, or energy drain.
Immunity to any effect that requires a Fort save unless that spell also targets objects.
Not subject to death via massive damage.
Can not be raised or reserected
Bonus hit points based on size, as listed on page 307 in rMM.
Does not eat, sleep, or breathe.
Object vehicles start with base ability scores of 10 before being modified for size above or bellow medium using the chart on page 291 rMM. The exceptions are Inteligence, and Constitution scores which have starting scores of "-".
Object vehicles are Mindless.

Construct [vehicle]:
These are golem crafts. Animated objects with the ability to move and act on their own.
As constructs they also get the benefits of the construct type:
d10 hit dice
no good saving throws (a fort save may be needed for vehicles from time to time)
No CON score (some vehicles are alive and have con scores)
Immunity to all mind-affecting effects.
Immunity to poison, sleep, paralysis, stunning, disease, death effects, and necromancey effects.
Cannot heal damage on their own, but can benefit from repair.
Not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, or energy drain.
Immunity to any effect that requires a Fort save unless that spell also targets objects.
Not subject to death via massive damage.
Can not be raised or reserected
Bonus hit points based on size, as listed on page 307 in rMM.
Does not eat, sleep, or breathe.
Object vehicles start with base ability scores of 10 before being modified for size above or bellow medium using the chart on page 291 rMM. The exceptions are Inteligence, and Constitution scores which have starting scores of "-".
Object vehicles are Mindless.
Damage Reduction 10/adamantine
NOTE: because they do not have object types, these vehicles do not have hardness scores, and take damage normaly.

Plant [vehicle]:
Plant vehicles are ships grown from groups of smaller plants, or a single larger plant. They are living but have nearly no movement abilities on their own and are not exactly creatures despite being living.
d8 + con modifier hit points
Good Fort save
immunity to all mind affecting effects
immunity to poison, sleep, paralysis, polymorph and stunning.
not subject to critical hits
plants breathe and eat (after a fashion), but do not sleep.
Object vehicles start with base ability scores of 10 before being modified for size above or below medium using the chart on page 291 rMM. The exception is inteligence, which has a base score of "-".

Undead [vehicle]:
undead vehicles are rare for a few reasons. Corpses that large generaly mean killing a very big creature of many smaller ones. both options are hard enough, but you are also faced with the problem of animating something that large. lastly, there are few benefits to using an undead vehicle over simply an object one.
D12 hit dice
no Con score.
good will save
immunity to mind-affecting effects
immunity to poison, sleep, paralysis, stunning, disease, and death effects.
immunity to critical hits, nonlethal damag,e abiltiy drain, or energy draing, damage to Str/Dex/Con, fatigue, and exhaustion.
Can not heal damage on its own unless it has an inteligence score. takes damage from cure spells, and is healed by inflict spells.
Not at risk for massive damage.
Not affected by raise dead or reincarnate spells. Ressurrection adn true ressurrection powers can affect it by turning it into the creature it once was... which wasn't a vehicle and means expelling all vehicle systems and occupants.
Undead do not breathe, eat, or sleep.


Personal notes: having written that up, I find it a bit hard to work with. I've tried a bit to hard to make vehicles too close to creatures. I'll have to work that out.

maybe latter, as part of a follow up project I can make a creature template that will allow for mixing monster & machine a bit more, but for now I think I need to seperate them out a lot more. (but not at 3:44 am)

 

[BlackJaw]

While I'm at it lets talk a little bit about terms and pricing concepts.

A vehicle is defined by it's type, size, hit dice, emphases, special systems, and weapons.

Types are construct, plant, aberration, undead.

Size uses the basic size listing in D&D. We extended that into some extra versions of collossal for realy big ships (they did something similar in Draconomicon for advanced epic dragons too, and dragon star has something along those lines for its non-grid skill based vehicles) each size has a range of hit dice it covers.

Hit Dice is just that, hit dice. They are used to determine hit points. players could roll for the ones on their vehicle, but most DMs will just find it easier to stat them like monsters. divide the dice type in half and add .5 then multiply by the number of hit dice.

Emphases are how you list the focus of the vehicle's design and construction. There are 4(?) Emphases: Weapons, Engines, Armor, and Support. vehicle builders put ranks in them to increase functions related to that emphasis. Vehicles have a total number of empahses ranks equal to their number of hit dice, and all must be spent.
Weapons = space for weapons
engines = fly faster, with more manuvering, or slower without dropping like a rock.
armor = get thicker armor for a higher armor class
support = get special systems

Special systems are aditional or special functions of the vehicle not easily covered by a emphasis. Zepplin or hot air balloon like blimps/balloons... force sheilds, interior space, cargo space, etc. A vehicle gets one system slot at 1st hit dice, and one more every 3 hit dice it has (3, 6, 9, 12, 15, etc). The system must still be purchased individualy, and may have requirements for the vehicles it can be placed in. special systems may be allowed or disallowed based on setting restrictions. Emphasis ranks in Support gets you extra special system slots beyond the every 3 hit dice rule. 1 rank = one more speical system. the cheapest ones are cargo, interior space, and extra fuel space.

Weapons are vehicle weapons. Having an emphasis in weapons provides you with weapon slots, but not the weapon itself. They must be purchased seperatly. some weapons are larger then others and require combining weapon slots to fit them into the vehicle. Some weapons are simple to make based off those found in the DMG (balistas etc) others will need a speical mechanic. cost increases, size increases... you get more damage, a weapon no longer mounted (turrets), better or difrent damage types, smaller requirements on power drain (if it uses power instead of ammo)...etc. I figure a 1-1 ration on weapon slots to weapon emphasis ranks. because getting larger weapons requires more ranks to fit, that should keep larger vehicles from have a to many guns, although if your building a star destroyer, you'd need 30-60 guns wouldn't you?

Build a gun mechanic:
base price is for a "medium sized" gun (what you get with 1 slot of weapon emphasis) that fires once before being reloaded as a full round action. It does peircing damage and uses ammo instead of power. (A simple small cannon). For a price you can do various upgrades: change from reloading as a standard action to standard, standard to move, and move to free (automatic) allowing it to be fired without being reloaded by hand. For a price you can also change the type of damage from piercing to bludgeoning, or slashing (fantasy weapons after all), or even to energy weapons... think of magic ballistas that fire bolts of lightning, or laser guns that shoot heat beams (fire damage). For an even larger price you can get sonic, acid, force, etc. Doing energy or force damage can also let you switch to power instead of ammo. power is done in charged (provided by special systems) and a basic weapon uses 1 charge per shot. Charges reset at the start of each round. For a price you can also get more damage from the gun, but that cuases it to grow in size as well (and increases ammor or power usage). every time you add 1 rank of weapon emphasis to the gun it gets 1 size larger. You can have a weapon up to one size larger then that of your vehicle. Increasing the size of a vehicle weapon can also be used to allow it to swivel about easier (use the wielder's size bonus or penalty instead of the vehicles) or increase ammo capacity (or decrease power usage.)

 

[Wyvern]

checking in

Sorry I haven't contributed in a while. My internet access has been more limited lately, and when I did get around to checking in, I was daunted by the length of the new posts in the forums. It's taken me a couple of weeks to find the time to read through them, but now I'm up to speed again.

When I first read your idea of using "classes" to build vehicles, it wasn't to my taste, but as you went into more detail on how it would work, it began to grow on me. In truth, it doesn't seem that different from the previous system (which I liked just fine, incidentally, as far as the overall design was concerned; most of the problems were in the details), rewritten so that it flows better. The basic idea is the same: you get a number of "slots" for components equal to the vessel's hit dice, which is dependent on its size. The most complicated part was (and still is, it would appear) the calculation of power, speed, maneuverability and lift. Otherwise, it was quite straightforward, which makes me wonder if this "point-based" version that you talked about was a derivative of the slot-based system which I never saw.

Some questions came to mind as I was reading through the new ideas. First of all, aside from the various components, what stats would be advanced by the various "classes"? ("Emphasis" sounds strange to me; I think "function" or "focus" would be a better name, but that's just my personal preference.)
- Hit dice, I agree, should depend on the base type of the vehicle.
- Skill points are a non-issue in the case of vehicles that lack Intelligence scores, but what about those few that *do* have them? How many should they get? Would it be determined by "class" or by base type (all the base types you listed get 2+Int points per level).
- Base attack bonus, IIRC (it's been awhile since I read the combat rules) depends on the person firing a weapon, not on the vehicle it's in. What about "natural" weapons, though, such as rams? Is the BAB for those weapons intrinsic to the ship? If so, is it determined by the base type or by the "class" of the ship?
- Saving throws: it looks like you're also using base type as a determinant for saving throws. Again, I have no problem with this.
- Feats have been replaced by "special features".

The main thing I disagree with is the idea that all the "classes" should gain the benefits of the other classes at a slower progression. In particular, I don't think that classes other than "Weapons" should get weapon slots. Otherwise, how do you build a vehicle without weapons? I'm also wondering about engines. Do all "classes" give a number of points to be distributed among speed, maneuverability, and lift, or do you only get these from levels in the Engine class?

This leads to the next question, which is how size affects speed. Realistically, a large vessel ("large" in a comparative sense, not the d20 sense) should need a greater number of additional engines than a smaller vessel to achieve the same increase in speed or maneuverability. In the last version of the rules, this involved a table. Is that still the case?

In the same way, a large vessel needs proportionately more fuel, life support, and crew quarters. I can see a case being made that these should be "built-in" features of all the classes in the same way that hit points are, but I didn't like the fact that devoting one special feature slot to "extra fuel" grants the same benefit regardless of the size of the vessel. Also, how do you deal with ships that don't need fuel or life support, such as sailing vessels? Perhaps the easiest method is to count them as a percentage increase to the base cost of the vessel. (This also allows for ships that use higher-grade fuel to pay a higher percentage in exchange for better fuel economy.) As far as crew quarters are concerned, perhaps a ship that only needs a skeleton crew, such as a freighter, can trade crew space for cargo space, fuel tanks or other components.

The last topic that I want to raise is tech levels. It might seem that this would be better dealt with after the basics have been nailed down, but I have an idea on how they could be incorporated into the core design in order to reduce complexity later on. These are just some ideas from the top of my head, understand, not a fully fleshed-out ruleset.

My basic idea is that each component should have a base cost associated with a base tech level. If you build a vehicle using components with a tech level *lower* than the current achievement level of your home cosmos, you get them at a reduced cost (say -20% at -1 level, -50% at -2 levels). This should bottom out at -2 levels; in the modern day, a catapult probably isn't any cheaper than a cannon. You can also buy "state-of-the-art" components one level higher than the norm at twice the base cost, but only if the GM rules that they're available.

(For magical components, where cost is often directly proportional to the spell level, the above would not apply. Instead, the best method would probably be to give all the costs at achievement level 9, which is the D&D standard, and then increase them accordingly for lower achievement levels.)

The point of this rule is to represent in a simple fashion the fact that the production costs of new technologies decreases as they become more commonplace. You can also modify it for technologies that exist at multiple levels of sophistication across several tech levels, such as rocket engines or guns. With engines, for example, you get a certain number of points per tech level to allocate to speed, maneuverability, and lift. In the case of weapons, you might have a table showing the basic stats (damage, range, accuracy mod) at each tech level. The base cost of the component at your own tech level would be a constant regardless of tech level, but you could "downgrade" by purchasing inferior components at a reduced cost. (Is that clear enough?)

Wyvern


P.S. One last minor quibble: I don't like the way you've defined "decks". Besides the fact that decks aren't enclosed in all ships, I don't see the point of making it a special component. If you want a co-pilot station, just make that a component in its own right.

 

[BlackJaw]

Sorry I haven't contributed in a while. My internet access has been more limited lately, and when I did get around to checking in, I was daunted by the length of the new posts in the forums. It's taken me a couple of weeks to find the time to read through them, but now I'm up to speed again.

Good to hear from you again. I'm a lot like a some pet dog. When people leave I sort of assume that I will never hear from them again (and will therefore be left to slow lonely death in an empty house) and when they show up again, I'm very happy to see you. Don't worry, I won't lick your face. OR: Hey! Nice to see you again!

When I first read your idea of using "classes" to build vehicles, it wasn't to my taste, but as you went into more detail on how it would work, it began to grow on me. In truth, it doesn't seem that different from the previous system (which I liked just fine, incidentally, as far as the overall design was concerned; most of the problems were in the details), rewritten so that it flows better. The basic idea is the same: you get a number of "slots" for components equal to the vessel's hit dice, which is dependent on its size. The most complicated part was (and still is, it would appear) the calculation of power, speed, maneuverability and lift. Otherwise, it was quite straightforward, which makes me wonder if this "point-based" version that you talked about was a derivative of the slot-based system which I never saw.

"Class systems" were not to my taste when some one brought them up a long time ago (back when I arged for a slot/point buy type system). It is onely recently that I decided to look at it again.
Yah, it's just a reworking of the same basic concepts: that many ship stats are tied directly to number of hitdice which are in turn connected to the ship's size. each hit dice represents some space in the vehicle devoted to a single feature, or part of a larger feature. It's a nice idea but it's proved hard to work out. The biggest problems come from it being:
1) Very complicated (so much so it became easy to make a vehicle that couldn't fly, or fly well, unless you had a deep understanding of the system... something we have but some one who downloads the book would see as a collection of odd math problems standing between them a vehicle).
2) Needing a lot of seperate components to cover a multitude of possible or interesting options (I mean a lot because we are not focusing on a single collection of tech or magic levels).

Still I pressed on with the concept of each hitpoint connecting to a single component (although some would need more) and it became harder. We had a massive (unfinished) list of components... to make it more usable I started condensing... instead of a collection of various engines I was working on 1 or 2 engine stats that scaled and could be configued instead of a seperate component for each type. I did the same with many weapon concepts... etc etc etc. Well the result was that I started to see things as being less and less complicated. Only a handful of very spicific systems need their own custom stats (sails, and zepplin blimps, force sheilds, etc) while most functions of a craft could be done using simple rules... and then it hit me: with everything all simplified, why not make most of hte basic functions classes, with one class being for the odd special systems? Many of the things I was working on all of a sudden felt a lot like class features and I realized presenting the construction system as being a lot like a character creation would make it easier to use and understand for most people that knew D&D 3.0/3.5/etc at all. It is that last feature (the ease of learning) that makes me such a big fan of this, although I have had other ideas as of late, and as this is the most important feature of the latter half of hte book, I'd love a lot of help to get it right.

Some questions came to mind as I was reading through the new ideas. First of all, aside from the various components, what stats would be advanced by the various "classes"?

I've been asking for help with that. I think some of my ideas on the topic swung wide into being TOO class/character like. I think a blance is needed (between the older component and newer class ideas... call it presentations of nearly the same ideas.)

("Emphasis" sounds strange to me; I think "function" or "focus" would be a better name, but that's just my personal preference.)

I hate naming stuff sometimes. A spicific name for everything like this will be needed eventualy, but for now, as long as we all know what we are talking about.

- Hit dice, I agree, should depend on the base type of the vehicle.

I like this idea still too.

- Skill points are a non-issue in the case of vehicles that lack Intelligence scores, but what about those few that *do* have them? How many should they get? Would it be determined by "class" or by base type (all the base types you listed get 2+Int points per level).

I figure (these days) having an inteligent craft would require having a special "AI" feature in the ship (something needing a special component/level/"feat" devoted to it) That would come for "free" on some types of vehilces (like the living ship-aberation and undead types... all others are non-inteligent by default) although what having this does is sitll up for debate. It would be easy to say that the ship has skill points based on hit dice, and a will save... etc. The hard part here is to define what a living vehicle can do without a pilot? can it fly on its own? use weapons on it's own? what if the pilot and ship are not in agreement on how to fly or what to shoot at? If it can fly itself, isn't it a vessel-creature instead of a vehicle?! Yes this is a bit confusing... but something to be delt with after the core mechanics are nailed down a bit more. As a final note on this topic, I figure adding an "on-board inteligence" to a vehilce would be mechancialy similar to sticking a ring of a sustinence on your co-pilot and then welding him into the co-pilot seat. He would need his own saves, ability scores, skills, etc... just like a real character... only he is stuck in the ship, and in some ways his the ship... but you can still design ships without them.

- Base attack bonus, IIRC (it's been awhile since I read the combat rules) depends on the person firing a weapon, not on the vehicle it's in. What about "natural" weapons, though, such as rams? Is the BAB for those weapons intrinsic to the ship? If so, is it determined by the base type or by the "class" of the ship?

Ramming attacks involve piloting checks. A ram weapon would allow you to be better at it (deal more damage, and take less yourself) but there is no attack roll in a ramming attack.
Anyway: as far giving BAB with class levels... again this would be tied to only inteligent vehicles because "stupid" vehicles would never make attacks, their pilots and passengers would.

- Saving throws: it looks like you're also using base type as a determinant for saving throws. Again, I have no problem with this.
- Feats have been replaced by "special features".

Yah, I agree. As long as we all know that the only save a ship needs that the pilot doesn't provide is Fort. Will saves are for pilots (or living ships) and reflex is provided by the pilot (and the living ship would have to have one to pass along... although it might use Inteligence instead of dexterity?) Again a lot of this is just what do we do about living ships?

The main thing I disagree with is the idea that all the "classes" should gain the benefits of the other classes at a slower progression. In particular, I don't think that classes other than "Weapons" should get weapon slots. Otherwise, how do you build a vehicle without weapons? I'm also wondering about engines. Do all "classes" give a number of points to be distributed among speed, maneuverability, and lift, or do you only get these from levels in the Engine class?

This is one of those things I was looking for feedback on, and thanks for the feedback! Yah, I think I may have been extending the Character Class concept out TOO MUCH. If we make it a bit closer to the component system we had before it is likly better. That is to say you only get the benefits of the levels you take. There are no free weapon slots, you much get them through taking weapon levels. There are no free special-system slots, you get them only through taking the systems levels. The one thing here to keep in mind is that you should be able to make any vehicle you design fly. It should be inherent in the system that if you took nothign but weapon levels, you ship would fly with the "minimum speed and manuverability" for a vehicle (or a vehicle of its size) and if you want it faster, you must take ranks in other systems. This removes the complicated concept of finding a balance between the right amount of power, engines, feul, lift, speed, etc... You start out with a default balance and then can up any one of a few special features to meet your design goals by taking engine levels.

This leads to the next question, which is how size affects speed. Realistically, a large vessel ("large" in a comparative sense, not the d20 sense) should need a greater number of additional engines than a smaller vessel to achieve the same increase in speed or maneuverability. In the last version of the rules, this involved a table. Is that still the case?

Yes, if you have a larger vehicle, you will need to devote more levels to engines to get any benefit. For smaller crafts it might be enough to devote 1-3 levels to engines to get a bit of an upgrade, but for something larger 1-3 levels in engines wouldn't change a thing. The exact ratio is not figured yet, but essentialy, yes the old "you need to put more in to get more out" concept is still the best one I can come up with. yes it will be table too.

In the same way, a large vessel needs proportionately more fuel, life support, and crew quarters. I can see a case being made that these should be "built-in" features of all the classes in the same way that hit points are, but I didn't like the fact that devoting one special feature slot to "extra fuel" grants the same benefit regardless of the size of the vessel. Also, how do you deal with ships that don't need fuel or life support, such as sailing vessels? Perhaps the easiest method is to count them as a percentage increase to the base cost of the vessel. (This also allows for ships that use higher-grade fuel to pay a higher percentage in exchange for better fuel economy.) As far as crew quarters are concerned, perhaps a ship that only needs a skeleton crew, such as a freighter, can trade crew space for cargo space, fuel tanks or other components.

"precentage" mechanics are not commonly used in d20 and I'd like find another way rather then make that the system here. This stems with keeping it with d20 "characteristics" as well as the fact that taking 33% of a number of HD that may be a prime number in the hundreads is rather ugly and involves a lot of rounding.
The best way to deal with this (or at least the one most often used in the PHB for things like this) is a table. Larger the craft the more fuel space is needed to get any more lenght of time out of the engines... just like with engines, and armor, and just about anything else that should scale. I have not yet worked out how to best work with fuel issues because the type of fuel effects the setting. Atomic/etc generators last a long time, while a petro-type tank on an aircraft or jet lasts hours or less...
As for life support... ship size has less to do with it then number of people. more components devoted to life support means more people can live on the vehilce. larger vehicles tend to have more people on them, and thus need more components for life support.

The last topic that I want to raise is tech levels. It might seem that this would be better dealt with after the basics have been nailed down, but I have an idea on how they could be incorporated into the core design in order to reduce complexity later on. These are just some ideas from the top of my head, understand, not a fully fleshed-out ruleset.

The issues here is that as I removed spicific components in favor for a single generic engine mechanic which is now just called "engine level" it made giving tech level less then possible. I do agree that building one into a component system is a good idea (although the complicated one we had before was too complciated. Tech/magic/Psionics or even tech/fantasy would be ok. 6 types of tech, various magic types, and psionic disciplines... that's far too much. History Lesson: The componenent system is based of the Alternity ship system that I loved so much. That system had a tech ratting for all the game's gear. While the weapon's and armor chapeter covered stone age through mater-energy converstion tech 9, the chapters on vehicles had only a few components for tech 4? (50s-modern day tech) and most were for the same tech level of the inherent setting (Star Drive) with a few upgraded ones for the latter tech levels. Their latter space ship guide book held pages of charts for the various tech levels of gear, and it was still modern tech through a bit of more advanced stuff. Our project covers a larger time spand and includes a lot of fanatasy stuff of a handful of types (spelljammer-ish magic sailing ships vs steam-punk...etc) so to make a large enough selections of individual components (each having their own tech ratting) would not be easy, and it would be far to massive.
Now one theory we tossed around (and you were one of the players in that game of toss) was that we would just put some basic things in the first release then then build collections of gear and sample ships and setting ideas by setting and release them seperatly. (Comsmonomicon: Steam-punk accessory, etc). I still like the idea of making a collection of add-ons by setting type, but I also think components would be too numerous and to easy replaced with simplified guides (like the current Engine level instead of 20+ engines seperated by helicopter/jet/prop/etc.

That said: your tech level is still not only valid but possible... but it needs tweaking a bit to fit.
>> Engine levels can not have tech levels outright... but what if we modifiy the mechanics a bit. If your using a vehicle of the normal tech ratting for your setting then when you compare engine points in speed/etc to the Table, you just look at the listing for vehicles of your size, but if you use a more advanced tech (jet engines instead of prop planes) you can look at the listing for a vehicle one size smaller. If your using out-dated tech you use the listing for one size larger (making you much slower and less manuverable).
>> Weapons with seperate tech levels. The "Cannon" mechanic that lets you build a weapon from scratch might need some work to tie tech level into it, but it could be done without much work. Maybe high tech weapons use larger damage dice while low tech ones use smaller ones? All other weapons have seperate listings (ballistas, etc) so that works as you describe.
>> Armor is a hard one for tech levels. putting levels of armor on a vehicle just ups it's armor class (more levels are needed for larger vehicles).
>> Special systems: special systems have seperate listings and thus can generaly have seperate tech levels.

Now I wouldn't generlay allow or recomend allowing tech of more then 1 level above "standard" tech for the setting, and lowering price for tech, as you said, would be done no lower then 2 ranks (maybe 1 again, as older tech would be generlay so outdated that it would cost a lot to make replacement or needed parts, etc. As a film student at SFSU I learned that a lot of the budget went to get replacement parts for their old cameras/etc... and they were stuck doing that because they never had enough money on hand to start getting newer cameras (which cost a lot to buy but would cost less to get replacement parts for!) Anyway, I do like this idea, and your right, that using one meathod or another could be fairly easily done to make this built into the system and thereby make it more flexible without making it more complicated then it needs to be.

P.S. One last minor quibble: I don't like the way you've defined "decks". Besides the fact that decks aren't enclosed in all ships, I don't see the point of making it a special component. If you want a co-pilot station, just make that a component in its own right.

Ok, works for me.

Good to hear from you again!

 

[Wyvern]

The hard part here is to define what a living vehicle can do without a pilot? can it fly on its own? use weapons on it's own? what if the pilot and ship are not in agreement on how to fly or what to shoot at?

Good questions. Here are my initial thoughts on the topic. I can think of three basic possibilities:

1) The vessel automatically overrides the pilot. (Not much fun for the pilot, especially if you've got an Evil GM.)
2) The pilot automatically overrides the vessel. (Maybe the best solution if you're talking about a computer AI or other intelligent construct, but it doesn't seem realistic in other cases.)
3) The pilot must succeed at a contested Will save to override the vessel. (I don't like this one much myself, but it is an option.)
4) The pilot must meet certain conditions in order to pilot the vessel at all, but if he does his control is absolute. In the case of undead or construct vessels, you might say that only the vessel's "creator" can control it, or that you need a special magic item (like a rod of dragon control). You could use the latter option with aberrations too. Perhaps there's a device that allows the pilot to "become one" with a living vessel. (This is the best option IMO because it allows so many different possibilities.)

"precentage" mechanics are not commonly used in d20 and I'd like find another way rather then make that the system here. This stems with keeping it with d20 "characteristics" as well as the fact that taking 33% of a number of HD that may be a prime number in the hundreads is rather ugly and involves a lot of rounding.
The best way to deal with this (or at least the one most often used in the PHB for things like this) is a table. Larger the craft the more fuel space is needed to get any more lenght of time out of the engines... just like with engines, and armor, and just about anything else that should scale. I have not yet worked out how to best work with fuel issues because the type of fuel effects the setting. Atomic/etc generators last a long time, while a petro-type tank on an aircraft or jet lasts hours or less...

I don't know what you thought I meant, but when I mentioned percentage adjustments, I was talking about a modifier to the base price of the vessel, not the HD. It also wouldn't have to be anything complicated like 33%; 10% is easy enough to calculate. What I had in mind was adding X% to the base price of a vehicle if it needs a fuel supply, and another X% if it needs life support. A vehicle that doesn't need fuel (because it uses sails instead of engines) or life support (because it's only used in atmosphere) wouldn't bother with these costs. However, since making that suggestion I've had a better idea about how to handle fuel, which I'll explain in a bit.

As for life support... ship size has less to do with it then number of people. more components devoted to life support means more people can live on the vehilce. larger vehicles tend to have more people on them, and thus need more components for life support.

Good point. So, any thoughts about how this could be reflected in the rules?

The issues here is that as I removed spicific components in favor for a single generic engine mechanic which is now just called "engine level" it made giving tech level less then possible.

I think you may have misunderstood what I meant. I'm not suggesting that we need a list of different types of engines for different tech levels. What I meant was that the number of "movement points" you get for one level in the Engines "class" could be determined by the baseline tech level. At its simplest, you could just say that you get (TL+1) movement points per level of Engines. (The "+1" is because the scale starts at TL 0: Stone Age.) The base cost of one level of Engines is a constant regardless of Tech Level, but you could upgrade your engines to a higher TL by paying more, or get a discount by downgrading them to a lower TL.

Using this system, you can then calculate a vehicle's speed without needing a table. First, add up the number of movement points allocated to forward motion ("speed points" hereafter). For each multiple of the vehicle's total hit dice, it moves 1 square (30 ft). Therefore, a 40-HD ship with up to 40 speed points would have a maximum speed of 30 ft; with 41-80 speed points, its speed would be 60 ft, and so on.

For maneuverability points, each multiple of the vehicle's hit dice above the first improves its manueverability by one class. So a 40-HD ship would have clumsy manueverability with 40 or fewer mp's; poor maneuverability with 41-80 mp's, etc..

On reflection, I don't think there's any need to bother with "lift points" and minumum speed. It may be more realisitic, but it's not any more fun. Just say that a vehicle must have Good or better manueverability or a dirigible in order to hover. (As a side note, I think a dirigible should double the vessel's effective hit dice for the purpose of determining maneuverability.)

Incidentally, a side effect of these rules is that you could never exceed the minumum speed of 30 ft using Stone Age engines. To go faster, you'd need magic (which would use a different formula to calculate speed points) or sails (which I'm presuming are treated as a separate type of component from engines).

The same type of rule could be applied to fuel and power as well (you might want to consider making these separate "classes"). For every level of Fuel you add, you gain (TL+1) units of fuel. The total fuel divided by the hit dice gives the vehicle's range in, say, hundreds of miles. As with engines, you could pay more to get high-grade fuel with an increased TL. Power would work on the same principle; the higher the TL, the more units of power you get per level. In this case, the size of the vessel doesn't matter; the power needs are determined by adding up the power consumption of individual components. (You could also have special components that allow you to convert fuel to power or vice versa.)

Wyvern