Inventor Feat!

Okay! I have a character who is an inventor, but is not and will not be an Artificer. Mostly because he is already level 7, MC Rogue/Wizard, and his build is...built...on the story that has happened thus far.

So, in order to help make running this concept in a balanced fashion easier on me and the DM, and to help me in the games I run if someone wants to either gain even more tinkering on their artificer, or gain some tinkering as a non-artificer, without it just being a case of "the DM makes it up as they go".

So, my solution is to build a feat for being an Inventor.

Design goals:

1. A feat that sits below the "broken" feats like Sharpshooter and GWM in power level, even if only just.

2. A feat that the rules of which are easy to apply.

3. Beneficial to Artificers who want greater specialisation and non-Artificers who want to dabble. Like Ritual Caster, which is useful regardless of class, so long as you don't pick wizard as a wizard.

4. Codify non-magical and/or common magical invention in a way that's easy to use.


So, I think that one part of this is to make all inventions that force a save use the 8+int+prof calculation.

Now, some of the things that my character wants to make follow, and I'd love to know what other people have seen players want to invent, and see if we can accommodate most of it in a simple, elegant, feat.

As for damage and cost, Do we make a chart of normal damage outputs by level, using the DMG spell creation table as a guide? Do we have a line on that table for cost by level, as well, and someone with this feat ignores the normal costing for similar adventuring gear?

Arrows of Acid and Alchemist's Fire are simple. In the current game, I spent a workday on each one in research, and two uses worth of gp, in order to make improved versions that get the same punch in a smaller amount of fluid. ie, same damage, but can fit in a hollow arrow or crossbow bolt.

The hollow arrow itself should be part of the feat, I think. And you can put one use of XYZ formulas in an arrow. The arrow costs 1gp each, and bc 5e is simple, it doesn't impact range or accuracy. You're paying for it, it doesn't need a drawback in use.

He is working on a tanglefoot arrow. One way to go is to make an arrow of Ensaring Strike or Entagle or Web, another is to take the Tangle Grenade (DMG?) and make it 5ft instead of 10ft, and use your Invention Save DC.

Frag arrow is simple in general, but what is the damage output guideline for this? The frag grenade is too much for a low level item, at least at any reasonable cost.

Smoke arrow should be pretty easy. I'd be fine with just using the smoke grenade, at your weapon's range.


Away from damage stuff: He wants to make a grappling shot style arrow/launcher device. My vision is either the cord is attached to a device on his crossbow, or on a specially made bracer the party ranger wears. The cord is spider silk thin, compacted into the arrow, and sticks into a creature or object or surface. As part of drawing the arrow, you hook a ring on the arrow to the device. The device allows you to pull the creature or object, or "pull" yourself to the surface, as a bonus action.

Glider Armor. Basically as the flying armor from Princes of The Apocalypse, except it doesn't necessarily allow full flight, but instead a gliding descent, or gliding flight controlled by acrobatics where you have to move your full speed every round until you land, and part of the movement is down unless you can catch an updraft. see, how to train your dragon.

Flashbang applies blindness and deafness on a failed save

Revolver Hand Crossbow is something he already has. Mechanically, it just replaces Loading with Reload 6 (bonus action or instead of an attack with the Attack Action to reload after 6 attacks) https://www.dndbeyond.com/magic-items/688037-revolving-crossbow


Advanced Cable-backed Double Recurve crossbow arms and bow is based on a combination of recurve composite bow technology, and cable-backed bows like this wabanaki bow, and the technology of the inuit cable-back bows. https://en.wikipedia.org/wiki/Cable-backed_bow


These would increase range and/or decrease the difference between primary range and long range, and could increase base damage, depending on balance considerations.

I forgot!

Such a feat should impact the cost and time to research and create this stuff, right?

So, I think research should take an amount of time similar to crafting magic items using the Xanathar's Guide rules. Perhaps use the DMG tables to determine a spell level equivelent, call in an Invention Level, and create a table with time and cost to research, time and cost to craft, and damage tier, to help guide inventing new items in a fairly balance way?

So, an Invention Level 1 item that deal damage might take 1 week and 100 gold to research, 1 day and 25 gold to craft an individual use, and deal 1d10 for single targets or 1d6 for AOE effects. Does the DMG have guides for how much damage a given condition is equivalent to?

I think that the closest current feat to base this one off in terms of power and versatility is Magic initiate. You're adding new powers, and it is popular, effective, but not generally regarded as game-breaking.

This feat gives you two new cantrip-level abilities that you can use a lot and one 1st-level spell ability that you can use once per long rest. This fits pretty well with the Inventor feat: You gain two inventions that are roughly equivalent to a cantrip in power and can make at minor cost, and one invention that you can only use once a long rest, but that is as good as a 1st level spell.

So one invention you pick could be the Alchemist's fire arrow: Its hollow shaft deals negligible physical damage but it splatters alchemist's fire onto the target dealing d10 fire damage. At 5th level the arrows might improve to deal more fire damage.

Or a more powerful version, but you can only carry one of could be based on Searing Smite.

Ensnaring Strike is a pretty good match for a tanglefoot arrow: it is already delivered by a weapon strike etc.

Grappling bolts etc could be based on Thorn Whip. Remove the damage but allow them to pull the user rather then the target, and perhaps increase the range a little.

Glider or parachute armour would probably based on Featherfall.

Flashbangs are probably beyond the limit of a balanced invention, even as your 1/day-use item. Causing only one of those effects on a single person is already a 2nd-level spell equivalent.
A better bet might be to base around Vicious Mockery/Frostbite: Deals d6 Thunder damage and causes disadvantage on your next attack.

Revolver hand crossbow is effectively a magic item. (And probably requires magic to function even more than a normal hand crossbow would. )

Cable-backed bows are already encompassed in the Shortbow and Longbow weapon categories of the table. It is a way of compensating for poor materials, and does not offer significantly improved performance compared to for example, composite bows or correctly-made longbows made of the correct wood.

Neither money for materials, nor downtime for research are useful balancing factors for a general-use feat. Different campaigns vary too widely in these factors. It may be possible to use them to balance in one specific campaign that you are running. However a different campaign and/or a different group may need very different values in order to provide the same level of balance.

edit: Thank you for the feedback and ideas. Modelling it after a feat which grants spells is a great idea, even if I disagree with the specific feat in question. Part of why is that the inventor should be able to learn further inventions, otherwise it will feel like a bunk feat. So, these items should have a cost and "rarity", a time restriction to learn them, and the Inventor should learn a few for free, and have some benefit with learning new ones. Thus, closer to a hybrid of magic initiate and ritual caster, or svirfneblin magic if it gave 1 less 2nd level spell and instead have access to a specific list of rituals you could learn.

Cap'n Kobold said:

I think that the closest current feat to base this one off in terms of power and versatility is Magic initiate. You're adding new powers, and it is popular, effective, but not generally regarded as game-breaking.

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I’d look more to Ritual Caster or the racial magic feats.

This feat gives you two new cantrip-level abilities that you can use a lot and one 1st-level spell ability that you can use once per long rest. This fits pretty well with the Inventor feat: You gain two inventions that are roughly equivalent to a cantrip in power and can make at minor cost, and one invention that you can only use once a long rest, but that is as good as a 1st level spell.

So one invention you pick could be the Alchemist's fire arrow: Its hollow shaft deals negligible physical damage but it splatters alchemist's fire onto the target dealing d10 fire damage. At 5th level the arrows might improve to deal more fire damage.

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I’d say that since you have to craft it, which has a time and money restriction, it can simply add alchemists fire to the effect of an arrow attack. So, I’d base the damage potentials roughly on the SCAG cantrips. I like cantrip style scaling, though. Also Searing Smite isn’t a bad way to go for a more substantial burning arrow.

Ensnaring Strike is a pretty good match for a tanglefoot arrow: it is already delivered by a weapon strike etc.

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yeah makes sense

Grappling bolts etc could be based on Thorn Whip. Remove the damage but allow them to pull the user rather then the target, and perhaps increase the range a little.

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doesn’t work for me at all, tbh. Gotta use that weapon range, or it isn’t worth making. The primary purpose is movement. Restricting pulling a creature toward you to 10ft could work. No reason to not do damage, though. The device cost at uncommon item level, arrows at maybe 20gp.

Glider or parachute armour would probably based on feathfall

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I’d rather stick with what I described. Limited flight isn’t that powerful. I’d call it an uncommon magic item that gives 60ft fly speed with some restrictions. 1/day Jump cast.

Flash-bangs are probably beyond the limit of a balanced invention, even as your 1/day-use item. Causing only one of those effects on a single person is already a 2nd-level spell equivalent.
A better bet might be to base around Vicious Mockery/Frostbite: Deals d6 Thunder damage and causes disadvantage on your next attack.

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I could get behind a minor flashbang like that, for sure. The full deal would be a higher level deal.

Revolver hand crossbow is effectively a magic item. (And probably requires magic to function even more than a normal hand crossbow would. )[\quote] Not especially. It just requires greater advancement than is generally assumed for dnd, which is the point of an inventor character concept. The only exaggeration of real life is the draw power combined with quick loading without some kind of lever to aid you, which all 5e crossbows assume as part of keeping the game simple and fun. *

Cable-backed bows are already encompassed in the Shortbow and Longbow weapon categories of the table. It is a way of compensating for poor materials, and does not offer significantly improved performance compared to for example, composite bows or correctly-made longbows made of the correct wood.

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it actually does, when combined with the same material quality of traditional bows. *

Neither money for materials, nor downtime for research are useful balancing factors for a general-use feat. Different campaigns vary too widely in these factors. It may be possible to use them to balance in one specific campaign that you are running. However a different campaign and/or a different group may need very different values in order to provide the same level of balance.

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Money is part of crafting. It’s soemthing to spend gold on, and it keeps crafting from being too handwavey for people who don’t want to hand Age it or let it be unlimited. Time is the primary balancing factor for crafting useful items in 5e, so a new option that works within 5e crafting will use that.


*I don’t care about arguments over realism. None of this is outside the norm for the inventor character concept.

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doctorbadwolf said:

edit: Thank you for the feedback and ideas. Modelling it after a feat which grants spells is a great idea, even if I disagree with the specific feat in question. Part of why is that the inventor should be able to learn further inventions, otherwise it will feel like a bunk feat. So, these items should have a cost and "rarity", a time restriction to learn them, and the Inventor should learn a few for free, and have some benefit with learning new ones. Thus, closer to a hybrid of magic initiate and ritual caster, or svirfneblin magic if it gave 1 less 2nd level spell and instead have access to a specific list of rituals you could learn.

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I'd suggest that you treat them as magic items rather than character abilities then, and use the feat as a method of entry into crafting them without needing spellcasting, and to improve the saves to the one based on your Int rather than the default save. Give a discount on the cost of creating (researching) them to counter the ongoing cost of using them.Magical items fit better with the concept: the only reason that I didn't suggest it before is that I didn't know you were using a crafting system.For example researching Alchemical Fire or acid arrows would be based on the cost and difficulty of creating a Flametongue sword etc.

I’d look more to Ritual Caster or the racial magic feats.

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Both of those feats are more limited than the mechanics that you seem to be after, both in versatility and outright combat power.

doesn’t work for me at all, tbh. Gotta use that weapon range, or it isn’t worth making. The primary purpose is movement. Restricting pulling a creature toward you to 10ft could work. No reason to not do damage, though. The device cost at uncommon item level, arrows at maybe 20gp.

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Hmm. So an arrow or bolt large and heavy enough to mount an effective grapple on the head, plus trail several hundred feet of rope capable of supporting a human's weight. I'd suggest at least some reduction in range.If all it does is mount the rope (perhaps giving advantage on strength checks to scale walls etc) that is one thing.However if you're envisioning the user being able to zip along the rope from the launching point to the grapple as a bonus action, that is quite powerful. Misty step/Flight ish level.

Not especially. It just requires greater advancement than is generally assumed for dnd, which is the point of an inventor character concept. The only exaggeration of real life is the draw power combined with quick loading without some kind of lever to aid you, which all 5e crossbows assume as part of keeping the game simple and fun. * it actually does, when combined with the same material quality of traditional bows. *

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I'm suggesting that they be treated as magical items, not so much because we can't even make that sort of thing an effective weapon even with 21st century technology, but because the items should be kept unique and special. Saying that your D&D setting does have the metallurgy and energy conversion capabilities as known tech begs the question of why it isn't in general use.Better to say that that item is magic/uses unique materials/requires constant maintenance by the only person who understands its principles, than to have to worry why those capabilities haven't revolutionised the rest of the setting. Which does actually bring us to the question: Can other people use an Inventor's inventions?

Money is part of crafting. It’s soemthing to spend gold on, and it keeps crafting from being too handwavey for people who don’t want to hand Age it or let it be unlimited. Time is the primary balancing factor for crafting useful items in 5e, so a new option that works within 5e crafting will use that.

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If you're balancing these items against the magic item system you're using in your campaign, then that is fine.Its only if you're treating them like additional character capabilities that issues occur. Money and time differ over different campaigns a lot and so a feat balanced using cash and time is going to be excessively powerful in a campaign where the user has plenty of both and so can stockpile their inventions, and extremely weak in a campaign without significant cash, access to shops and facilities, and downtime.

Cap'n Kobold said:

I'd suggest that you treat them as magic items rather than character abilities then, and use the feat as a method of entry into crafting them without needing spellcasting, and to improve the saves to the one based on your Int rather than the default save.

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Save DC based on pc stats is the plan for all crafted items that require a dc, outside of magic items that set a dc rather than using the wielder’s. For some items, like a tangler bomb, that will be weaker than the set DC, while others it will be stronger. The plan was never to treat them as abilities. I’ll have to look over my OP and figure out where to make that clearer, bc I had thought I’d made it clear already.

Give a discount on the cost of creating (researching) them to counter the ongoing cost of using them.Magical items fit better with the concept: the only reason that I didn't suggest it before is that I didn't know you were using a crafting system.For example researching Alchemical Fire or acid arrows would be based on the cost and difficulty of creating a Flametongue sword etc.

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flametongue seems too high level for alchemists Fire, which is a 50 gold item that anyone with Xanathars Guide and proficiency in Alchemists Supplies can make a use of as part of a long rest. Adding that to an attack isn’t a huge jump. It’s comparable to a first level spell, at best, and indeed the 1st level Smite spells do more. My thought right now is that research is comparable in time and cost to the spell level equivalent being added to your spell book. Maybe with time multiplied by some factor because research takes longer Than copying.

Both of those feats are more limited than the mechanics that you seem to be after, both in versatility and outright combat power.

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Eh, it’s less powerful in fact than simply winging it, which is the situation for any DM that wants to allow invention and crafting. It’s probably less powerful than RAW magic item crafting, which also doesn’t require a feat. The benefit is getting a couple inventions with the feat, and perhaps reducing crafting time for alchemical items and tinkered devices. The rest is just codifying invention crafting so that it’s under control.

So an arrow or bolt large and heavy enough to mount an effective grapple on the head, plus trail several hundred feet of rope capable of supporting a human's weight. I'd suggest at least some reduction in range.

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Realism doesn’t matter. It’s a fantasy inventor character. It’s spider silk cable so thin it fits inside an arrow. Cool. That’s all the explanation needed. As for range, I’d be fine with restricting it to the weapon’s optimal range. Anything else is too complicated and restrictive.

If all it does is mount the rope (perhaps giving advantage on strength checks to scale walls etc) that is one thing.However if you're envisioning the user being able to zip along the rope from the launching point to the grapple as a bonus action, that is quite powerful. Misty step/Flight ish level.

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yep, as I suggested in the OP, we can use spell level equivalents to determine cost and time to craft. This would be an uncommon item equivalent for the pulling device, and consumable uncommon item equivalent for the arrow, bc Misty Step is a 2nd level spell. (It’s definitely not on par with Fly) This has limitations Misty Step doesn’t, but greater range, and eats an attack and a bonus action. So, since uncommon items in the dmg have a max spell level of 3rd, and this is on par with a second, uncommon item pricing is used.

I'm suggesting that they be treated as magical items, not so much because we can't even make that sort of thing an effective weapon even with 21st century technology, but because the items should be kept unique and special. Saying that your D&D setting does have the metallurgy and energy conversion capabilities as known tech begs the question of why it isn't in general use.Better to say that that item is magic/uses unique materials/requires constant maintenance by the only person who understands its principles, than to have to worry why those capabilities haven't revolutionised the rest of the setting.

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this isn’t comparable to modern tech. It’s just a bow that uses techniques that never crossed streams before bows were made into sporting tools and then revolutionized with gear ratios. More importantly....I Do. Not. Care. About. Realism. A tinker bow that shoots greater distances with a bit more punch without being any bigger is well within fantasy inventor story territory. That’s all I care about. At all. Ever.

. Which does actually bring us to the question: Can other people use an Inventor's inventions? If you're balancing these items against the magic item system you're using in your campaign, then that is fine.Its only if you're treating them like additional character capabilities that issues occur.

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I really think my OP is based on a magic item assumption, but I will double check it after finishing this and update it if needed. Yes, these are balanced against (but are not actually) magic items. Like a crafter wand or +1 sword, anyone proficient can use it. Some items will require training or proficiency in tinker tools or alchemists supplies, just like wands require spellcasting ability.

doctorbadwolf said:

Save DC based on pc stats is the plan for all crafted items that require a dc, outside of magic items that set a dc rather than using the wielder’s. For some items, like a tangler bomb, that will be weaker than the set DC, while others it will be stronger. The plan was never to treat them as abilities. I’ll have to look over my OP and figure out where to make that clearer, bc I had thought I’d made it clear already.

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Rereading the OP with the knowledge that you're talking about accessing a campaign-specific crafting system that would be implemented alongside a magic item crafting system rather than a personal power boost like GWM or Sharpshooter, it is clearer now. I think that I just started thinking along the lines of balancing Inventor with other feats rather than balancing its creations against magic items and followed that train of thought instead.

flametongue seems too high level for alchemists Fire, which is a 50 gold item that anyone with Xanathars Guide and proficiency in Alchemists Supplies can make a use of as part of a long rest. Adding that to an attack isn’t a huge jump. It’s comparable to a first level spell, at best, and indeed the 1st level Smite spells do more.

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Adding that to an attack is a fairly major jump, particularly if the only limit is a minor gold cost. While the searing smite spell has a chance of continuing to damage its target, it also has restrictions on casting that prevent it from being used as effectively as these alchemical arrows could be. Being able to burn the equivalent of a spell slot every attack is noting to sneeze at either.In the same way that a direct boost to AC is more powerful than just a different method of calculating it, adding damage on to an attack is much more powerful than simply providing an alternative type of attack. If you're adding fire damage to every attack, you're looking at power equivalent to Flame Arrows or Elemental Weapon spells, or Flametongue weapons.

My thought right now is that research is comparable in time and cost to the spell level equivalent being added to your spell book. Maybe with time multiplied by some factor because research takes longer Than copying. Eh, it’s less powerful in fact than simply winging it, which is the situation for any DM that wants to allow invention and crafting. It’s probably less powerful than RAW magic item crafting, which also doesn’t require a feat. The benefit is getting a couple inventions with the feat, and perhaps reducing crafting time for alchemical items and tinkered devices. The rest is just codifying invention crafting so that it’s under control.

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I'd regard the cost as closer to the cost of researching the pattern of a magic item and obtaining the necessary component. - Which obviously isn't a meaningful cost if you don't require research or special components to create magic items of course.I'd suggest the feat could also grant proficiency in a tool set or kit as well.

Realism doesn’t matter. It’s a fantasy inventor character. It’s spider silk cable so thin it fits inside an arrow. Cool. That’s all the explanation needed. As for range, I’d be fine with restricting it to the weapon’s optimal range. Anything else is too complicated and restrictive. yep, as I suggested in the OP, we can use spell level equivalents to determine cost and time to craft. This would be an uncommon item equivalent for the pulling device, and consumable uncommon item equivalent for the arrow, bc Misty Step is a 2nd level spell. (It’s definitely not on par with Fly) This has limitations Misty Step doesn’t, but greater range, and eats an attack and a bonus action. So, since uncommon items in the dmg have a max spell level of 3rd, and this is on par with a second, uncommon item pricing is used.

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If you've decided to limit it to the short range of the weapon, that does rein in the power somewhat. I think the fact that it requires setting up before using would compensate for being able to travel over 100ft as a bonus action.

Cap'n Kobold said:

Rereading the OP with the knowledge that you're talking about accessing a campaign-specific crafting system that would be implemented alongside a magic item crafting system rather than a personal power boost like GWM or Sharpshooter, it is clearer now. I think that I just started thinking along the lines of balancing Inventor with other feats rather than balancing its creations against magic items and followed that train of thought instead.

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Fair enough. The crafting system is basically the Xanathar’s magic item crafting. I figure that way, I can easily just reference those rules, repeat some tables to prevent the need to cross reference a book, and make a second table that shows Invention Level compared to magic item rarity, and then the dmg damage by spell level guide as a guidepost for how much damage a given level of invention should be able to do. Can probably streamline all that some, but that’s the basic gist. It’s basically magic item crafting with some custom “magic items” that aren’t actually magic.

Adding that to an attack is a fairly major jump, particularly if the only limit is a minor gold cost. While the searing smite spell has a chance of continuing to damage its target, it also has restrictions on casting that prevent it from being used as effectively as these alchemical arrows could be. Being able to burn the equivalent of a spell slot every attack is noting to sneeze at either.

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again, time is the balance factor, just like with crafting magic items. The idea is to apply whatever rules or house rules you apply to magic item crafting. By assuming the DMG or Xanathar’s rules for magic item crafting, I can predict the balance within the context of a game in which magic item crafting is allowed. With time and money in a standard campaign, neither acid nor fire arrows will be close to at will until a level at which at will +2d6 or +1d4 ongoing is less than the sort of magic weapons people can get. A bow that sets things on fire on a hit would be uncommon, rare at most. Having to spend time and money for making an uncommon item in order to learn it, and then uncommon consumable price/time to make each one, is quite within that balance context.

In the same way that a direct boost to AC is more powerful than just a different method of calculating it, adding damage on to an attack is much more powerful than simply providing an alternative type of attack. If you're adding fire damage to every attack, you're looking at power equivalent to Flame Arrows or Elemental Weapon spells, or Flametongue weapons. I'd regard the cost as closer to the cost of researching the pattern of a magic item and obtaining the necessary component. - Which obviously isn't a meaningful cost if you don't require research or special components to create magic items of course.I'd suggest the feat could also grant proficiency in a tool set or kit as well.

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I’d say it’s closer to the power level of a consumable magic item that casts Hunter’s Mark or Hex. But even closer to having Booming Blade after level 5, but on a consumable magic item. Whether that is super powerful or not is dependent on how easy it is to reliably spend a month in downtime between every single adventure in a given campaign. But even if it is easy, that just makes it comparable to a magic weapon that adds 2d6 acid damage at will.

If you've decided to limit it to the short range of the weapon, that does rein in the power somewhat. I think the fact that it requires setting up before using would compensate for being able to travel over 100ft as a bonus action.

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Yeah, using the long range would be complicated and harder to balance. Possible upgrade option, though. The movement is roughly 2nd level spell, so still within uncommon item level, but it costs more because you have to make special arrows and a separate device. Creatures make an odd situation if a player wants to use it against them, but I figure ability check contest as grapple, pull the creature up to 10-15ft as a bonus action instead of traveling. Maybe further, or that plus extra damage. I’ll have to check out some 2nd level spells.

[MENTION=25643]ca[/MENTION]p’n kobold hey so this has been very valuable. I think I’ll either rewrite the OP or start a new thread with more focus, based on this discussion so far.

So the first question should always have been, what would a feat for magic item crafting look like.