D&D 5E Excerpt from a 5e naval supplement I'm writing

[bedir than]

That is an easy fix. Replace all mentions of "Cannons" with "Ballista". Unless the DM wants to go even further back, in which case your example of just having archers would work fine.

This is DnD. Replace "cannons" with spellcasters.

 

[RangerWickett]

Personally I wouldnt have chosen a river engagement as example of play especially when a galleon is involved as that ship type is rather unsuited for that task and no sane schooner captain would engage a galleon, even one as severly underarmed as this one.

Fifteen cannons on this galleon.

This would be an example of, say, a level 10 party. They're bad-asses, have a bit of interesting magic, and assume they can handle anything.

From your example it looks like you do not take wind into account? That always a tricky decision as wind was so important for Age of Sail combat but makes combat much more complicated. Will it be optional?

Since 5e is naturally pretty fast-and-easy in its rules, wind only exists in the base rules in the sense of 'low winds' limiting speed and 'high winds' making ranged combat harder and seas choppier. Bear in mind, this is the same ruleset where a 1st level character with a 10 foot running start might long jump 20 feet.

Optional wind rules are still pretty fast-and-easy. The ship that is most upwind has the weather gage and gets advantage on its initiative check. The first 'space' of movement that heads upwind costs and extra 1 point of speed. Not totally realistic, but simple.

The main danger or problem I see is that the naval combat you describe is much more modern than what most settings and campaigns represent. Most settings do not have cannons and guns and I dont think many DMs want to introduce them for naval combat as it would also making them available for other uses.
So if you want your rules to be "plug and play" you should also devote a larger part of the rules to medieval naval combat with galleys and early sailing shios which exchange archer volleys.

This system is primarily intended for ZEITGEIST and other settings with cannons - or settings like Eberron that would have 'arcane fusils.' If you don't have cannons, ship facing doesn't really affect your attacking options, and aside from ramming or setting sails on fire it's pretty hard to really damage the other vessel, so such naval engagements are a bit simpler. Ranges are a lot shorter too - 600 ft. max for longbows (and who brings 80 longbows on a pirate ship?) vs. 2400 ft. for cannons. ((Trebuchet work for pre-cannon big weapons, but they take up a lot more space.))

The rules I have for crew treat them as a sort of 'swarm of people,' with one shared hit point total, and how much HP the crew has determines how many attacks it gets. When crew make ranged attacks, they target an area and make one attack roll that applies against all creatures in the area.

For example, a crew of 80 might have an HP total of 400, and if you got into a boarding action would be represented by eight 'Large' tokens, representing a cluster of crew. Spaces adjacent to them are treated as difficult terrain for enemies, to make moving through a crowd more difficult. Each of those tokens gets to make one volley attack at a 10-ft. area, potentially hitting everyone in that area with one arrow. Since 'area attacks' do extra damage to crew, it's fairly easy to adjudicate two crews trading arrows, though the dice rolling could get tedious if there's nothing else going on in the scene. That's why a static environment is weak encounter design.

 

[RangerWickett]

This is DnD. Replace "cannons" with spellcasters.

I prefer 'arcane fusils.' Think 'staff of magic missiles' laid on its side. Has charges like a staff, so prolonged battles are out, but a spellcaster can recharge it.

Also, if you're going to spend 30,000 gp on a warship, you equip it with a few thousand extra GP of enchantments so it's a viable threat and won't be taken out by a single fireball.

I fully intend to be able to handle 'realistic' sailing engagements, but D&D is fantasy. The rules I'm writing are meant for fantastic games.

 

[Derren]

Fifteen cannons on this galleon.

That looks more like a carrack to me.

This would be an example of, say, a level 10 party. They're bad-asses, have a bit of interesting magic, and assume they can handle anything.

Yet apart from spellcasters it does not look like the level of the PCs affects the combat ability much. It seems to me that the best thing to do for the PCs would always be to close and board as in that case they get to use their superior melee fighting ability which increases with level instead of relying on the static stats of a ship.

This system is primarily intended for ZEITGEIST and other settings with cannons - or settings like Eberron that would have 'arcane fusils.' If you don't have cannons, ship facing doesn't really affect your attacking options, and aside from ramming or setting sails on fire it's pretty hard to really damage the other vessel, so such naval engagements are a bit simpler. Ranges are a lot shorter too - 600 ft. max for longbows (and who brings 80 longbows on a pirate ship?) vs. 2400 ft. for cannons. ((Trebuchet work for pre-cannon big weapons, but they take up a lot more space.))

Cannons didnt really damage the ship either. Sinking a wooden ship in combat is very hard. And speaking of fire, what are the effects of the ship being on fire? In your example the burning sails didnt seem to be much of a concern.
And even with longbows the facing is important as you can shoot a lot more arrows from the side than from the bow/stern. Don't forget that volley fire was kinda hard with all the rigging in the way.
And for some time people did use archers and cannons at the same time like with the famous Mary Rose.

The rules I have for crew treat them as a sort of 'swarm of people,' with one shared hit point total, and how much HP the crew has determines how many attacks it gets. When crew make ranged attacks, they target an area and make one attack roll that applies against all creatures in the area.

How is special crew handled like marines and sharpshooters in the rigging?
Speaking of crew, how are supplies and undercrewed ships handled?

Also, with the ability to target specific characters it seems to be incredibly easy to snipe individual characters.

 

[robus]

I specifically went with a more fantastical location because, well, I don't like D&D combats in wide open fields either. An interesting environment makes movement more meaningful. My preference is for naval combat to be like solving a puzzle. The foe and/or environment have some schtick you need to figure out how best to counter.

Well you did call it a "naval" supplement

 

[Ancalagon]

I like a lot of the things in your scenario - the lengthened rounds, the speed and links to knots, the various targeting areas (crew vs hull). On the other hand, two ships wouldn't fight in such a locale, and a small agile ship would very rarely engage such a stronger opponent.

I also note that under very difficult circumstances, 5/15 shot hits - was this a lucky roll?

questions/comments

- You can target the hull and the crew (good!), but what about targeting the mast/rigging?
- Different cannon munition... I wouldn't go crazy, but I think cannon balls (range/vs hull), chain shot (vs rigging) and grape shot (vs crew, shortest range) are things to consider.
- I worry that 5e might be too "coarse" with the advantage/disadvantage mechanism. For example, if a ship has disadvantage to maneuvers due to some local conditions, the enemy captain might forgo shooting at its riggings (no point, it's already at disadvantage), while in real life the enemy captain could do that to make things even *worse*
- another example might be the gun ranges. "short vs long" seems a bit... simplistic.
- back on cannons: A big factor here is the skill of the gun crew, not just for accuracy but for *firing rate*. A bad crew could fire maybe once every 5 minutes, while a skilled one could have 3 broadside in the same amount of time.
- If you haven't done so already, read a few of Patrick O'brian's novels
- as mentioned by others, tech era will really matter
- cannons will dominate naval warfare as they have waay more range than most spells
- "Civility" will matter. In the age of sail, there were unwritten but widely honored rules about surrender etc. However, some foes in a D&D world will *not* follow those rules and there will be fight to the death.
- that whirlpool spell... what level is that? You are correct to point out that "naval casters" would have "naval" spells... something like a burst of speed, fire control, fog cloud or "deflecting" a ship would all be immensely useful.
- "Familiar" specialist able to communicate long range with a speedy sea bird (for example), or skilled diviners, would also be very useful to scout ahead.

 

[Lanliss]

- that whirlpool spell... what level is that? You are correct to point out that "naval casters" would have "naval" spells... something like a burst of speed, fire control, fog cloud or "deflecting" a ship would all be immensely useful.

It was Control Water, a 4th level spell in the PHB.

 

[RangerWickett]

Thanks for the comments and questions.

I also note that under very difficult circumstances, 5/15 shot hits - was this a lucky roll?

The mechanics I have in mind for cannons is that normal ships have an AC of 15, and a normal gunnery crew has an attack bonus of +3, so most shots either miss or hit areas where damage doesn't actually cause any problems for the target.

For a cannon volley, you take five cannons and make one roll with a +10 bonus. If you match the AC, one shot hits, plus an extra shot for every 5 you beat the AC by. Since ships have 'damage thresholds' (detailed in the DMG; it's sorta like hardness), this lets volleys of light cannons actually hurt sturdier ships. It speeds up play, which is what 5e is all about.

That said, yeah, 5 shots hitting there is slightly above the curve. The Nergal would be making three attack rolls (d20+15 - crew skill +3, +2 for heave to, +10 for volley) vs. AC 20 (15 +5 for three-quarters cover), with disadvantage for range.

- You can target the hull and the crew (good!), but what about targeting the mast/rigging?

You can either get a lucky strike with a nat 20 critical hit, or if an officer directs the firing crew, he can take a -5 penalty to aim at a specific location for a single shot or volley. Rigging, however, takes half damage from most attacks (fire and chain shot do full damage), since there's not as much to hit.

- Different cannon munition... I wouldn't go crazy, but I think cannon balls (range/vs hull), chain shot (vs rigging) and grape shot (vs crew, shortest range) are things to consider.

Yep, though most of that goes in the 'advanced rules' section. I imagine a lot of groups will just end up on a ship for a single session, and not want to trawl through pages of options they probably won't use.

- I worry that 5e might be too "coarse" with the advantage/disadvantage mechanism. For example, if a ship has disadvantage to maneuvers due to some local conditions, the enemy captain might forgo shooting at its riggings (no point, it's already at disadvantage), while in real life the enemy captain could do that to make things even *worse*

Damaged rigging slows a ship. So if there are rough seas, and shoals you need to avoid, and your rigging is damaged, you'd have disadvantage on the piloting check, and if you succeed you might have spent most of your speed just going through one space. And there's always the GM's prerogative that if the rules don't model what could happen, you can just change things on the fly.

I've read Fire As She Bears, and while it does a great job of modeling a lot of granularity in sailing, it slows games down more than I'd enjoy.

- another example might be the gun ranges. "short vs long" seems a bit... simplistic.

That's a level of simplicity I'm okay with. Between the competing drives of 'scrape for every possible bonus so I win this game,' and 'keep things fast so I enjoy this story,' I lean in the direction of story.

- back on cannons: A big factor here is the skill of the gun crew, not just for accuracy but for *firing rate*. A bad crew could fire maybe once every 5 minutes, while a skilled one could have 3 broadside in the same amount of time.

By default, cannons take 1 one-minute naval round to reload. So it's often fire, jockey for position, fire, jockey for position. You can use an officer action to try to reload some cannons faster, but there's a risk of mishap that causes one of your cannons to explode. If the crew is depleted (i.e., at or below half its max HP), it takes an extra round to load.

 

[Ancalagon]

I think that +3, 1 shot per round represents a well trained crew... this *isn't* the norm though, as powder (or magical ammo etc) was expensive and not every captain trained their crew properly. Even the royal british navy had a fairly tight budget for this.

What cannon "size" do you have? Did you consider caronnades? ( see https://en.wikipedia.org/wiki/Carronade )

 

[RangerWickett]

Light cannons do 20 damage, range 300/1200. Normal cannons do 40 damage, range 600/2400. Heavy cannons do 60 damage, range 600/2400. (Mostly because I figure most gaming groups don't have a table where longer ranges would matter; in practice, people draw battle maps that fit on their table.) I'm still figuring out how to set, like, a 'Challenge Rating' and to balance encounters.

And it's fire one round (which is a minute long), reload the next round, fire the third round.

The attack bonus is just a basic +2 proficiency bonus, and a +1 Dexterity bonus for a military-trained crew. A normal merchant ship probably has +0.