Rules for Inventing [Archive] - Wizards Community

Rules for Inventing [Archive] - Wizards Community

Post/Author/DateTime Post
Limit
11-25-05, 12:46 AM I'm about to start a new campaign and I have decided to allow the renaissance weapons from page 145 in the DMG. One of my players asked about the revolver which is currently listed as a modern weapon and not allowed, but I think it'd be cool that over time, players could invent new fire arms. I mean, its not really a stretch for me to look at a repeating crossbow and want my gun to do the same thing.

So any thoughts on rules for inventing new weapons and possibly armor? I imagine that it would take a number of attempts, so it'd probably be a high DC that lower level characters couldn't pull off. But if a character dedicated themselves to it, they'd win eventually. I'd also like any thoughts you folks have on making guns with mishaps. Perhaps an invention check that only fails by five or less has a chance of the gun exploding later.

If there any rules for this type of thing in the existing books, please point me in their direction too :-)
Gilean
11-25-05, 08:30 AM Inventing new spells in DMG can be used as a start.
Require a new feat or skill focus to pull it off. It ought to take a lot of time and effort.
Limit
11-26-05, 01:12 PM Inventing new spells in DMG can be used as a start.
That is a good place to start, but I'm not sure how to determine a "level" for technology.

Researching an original spell takes one week per spell level and costs 1,000 gold per week. At the end, you make a spellcraft check DC 10 + spell level.

I suppose I could base the level on something like average damage. A revolver does 2d8 points of damage, so it's level would be 9? Change the spellcraft check to blacksmithing and then it'd take 9 weeks, 9,000 gold, and a DC 19 check to craft. That wouldn't make it too hard to invent something like the laser rifle though, which does 3d8, making it a level 13.5 weapon.

I could also make some sort of chart and just assign a different level to the weapons in the DMG base on my opinion of how powerful they are.

Any other thoughts or suggestions?
Lokiyn
11-27-05, 03:09 AM Try setting Dc checks per week, every month with 4 successful checks advances your characters "tech level" by a set amount, (say a year) or to the next tech milestone (i'm sure there is a timeline out there somewhere you can use. Or something similar.
sabrewolf
11-27-05, 09:50 AM Inventing new spells in DMG can be used as a start.
That is a good place to start, but I'm not sure how to determine a "level" for technology. <cut> Any other thoughts or suggestions?
To me, that bit and magical iten creation will posibly be your guidelines. Plus some lateral thinking and flavour to taste.. ;)
I´m planning fluff for a side-plot based on X-com: TFtD :evillaugh wich requires ´technology´.. except i´m in fact using techno-magery, I.E. magical itens that a commoner can operate after some training, not needing being a spellcaster..
Researching an original spell takes one week per spell level and costs 1,000 gold per week. At the end, you make a spellcraft check DC 10 + spell level.

I suppose I could base the level on something like average damage.
That can be used for research before the iten itself can be built. Itens on the same tech branch but piled crescent on the tree (say for example: a pistol, a rifle, a bigger rifle, a stationary cannon, a ship-mounted cannon) could have an ad-hoc to decrease the research time and price as you go up the tree.
That wouldn't make it too hard to invent something like the laser rifle though, which does 3d8....
To me, Itens are not much hard to create. New spells are.. But beter then just saying, why not put an example:

My Sonic Disruptor sequence: (it´d still in construction but these are the thoughts i´m basing myself of)

- Sonic Pistol: Similar to a hand-crosbow. Base spell "Produce Flame". Damge changed to Sonic ( i know one might say sonics are uncommon and an ad-hoc should be applyed, like Sl+1, but since it´s just an example i´ll keep it as is: also guns could deal fire damage as the unchanged spell). Range.. i cant remember and i´m not with my books right now, but if the spell´s reange increment is not enough, consider range enhancing metamagic into calculating or state all eapons have X range increment.

Basing on that, and considering the first base pistol to start, it´d be.
Produce Flame > lvl 1 spell...

Sonic Tech > Pistol weapon:
Range: As spell.
Rate of Fire: 1
Damage: 1d (sonic)
Research Cost = 1,000 gold
Research Time = 1 week,

Assembly Cost = 2,000 gold (i´d only halve the cost after a few was made or the tech was better underestood.. but you can make it 1k gold if wished)
Assembly Time = 2 days or,
Assembly Time = Crafting Rules, dependant on check rolls Vs Iten Cost. (i´d use that ´less one actually pull off and build a factory :P )

From that, i decided that the rifle and cannon would have 3d and 5d of damage. To that i can either think on the Empower Spell feat (not much likely) or compare with 2nd or 3rd level spells (or higher). I´d add up the damage dices for repeating weapons for claculation and use the Split Ray metamagic feat to actually give it many shots/round..

Mounted Weaponry or Seige / Ship Weapons would both need range improovements and get a x4 multiplyer for each size category as per normal magic iten creation (with at least 1 since it begins as a large device)

Mishaps: These are funny.. I guess the Gnome Artificer have some ruling about that, might be worth checking.. An idea could be a 5% chance per damage die with mishap damage = normal damage (1 shot or full shots) rolled on finished building and/or at each natural 1..

Wonder if that´s of use for you...

As for a laser weapon.. :plotting: :mage: :evillaugh "Searing Light" work well for it.. Use the Split Ray Feat for a repeating gun.. or... the Split Ray, Empower Spell, Twined Spell, Repeating Spell supper combo :devil: for a highly expensive but insanely destructive laser gatling maddness..
Gilean
11-27-05, 10:22 AM Cannons are not that hard to do. A tube with something giving a push when it is burned, that's how the simplest ones worked. Not hard once blackpowder or something similar is found.
Grizzled Gryphon
11-27-05, 11:02 AM Here are some things to consider, too. A spell, like produce flame, does it thing once. A pistol can do its thing as many times as you pull the trigger. So, maybe consider the damage as a means fo figuring out the equivelent "spell level" should be based on all the damage it can deal. Not over a year, or something, but how much damage it can do before reloading. Now, it is more like a damage over time spell, like Firewall, but you still want to add to it because unlike Firewall, you can decide when that damage is applied. Scorching Ray is a good example. What level do you have to be to get 6 rays? Find out what the highest level spell you can cast at that level, and you have your level that the pistol is closest to. I would increase the prices above what this implies, though, as any prototypes are HUGELY expensive. This goes in real life as well as in a game. For example, the prototype of the Ford Escort cost around 2 million. how much does the production version cost? I believe they started at around 12,000, back when they first came out. At any rate, you get the idea.

Also, remember that in real life, the cannon came first, then the rifle, and MUCH later the pistol. Sure, the first black powder weapon wa a little pot with an arrow sticking out of it, but after that came a mortat, then a cannon. The musket followed very closely after that, and then came the pisotl some time later. Just something to think about.

Now, the above was due to the need of something like a pistol was very low. After all, there were no "adventurers" running around. However, in a game world, that is very much the difference. I would imagine that rifles of any kind and pistols would be a VERY lucrative business. And, like any other business, whoever makes the best, makes the most money. And everyone knows, adventurers have LOTS of money. I could only imagine that there would be several "companies" trying for the best weapon that an adventurer could want. And, oh, the adventure hooks that leads too!! Rogues working for those companies trying to steal the PC's design, or the companies fighting for the rights to it, or the PC's getting hired to steal the designs of a rival company... wow, it is Shadowrun and D&D mixed together!! See? Guns ARE bad!! LOL. Of course, another possibility, one company wants some of its prototype guns feild tested. Enter the PC's. This can add some interesting twists to any game. While doing some other adventure, the party has to also contend with agents of other companies trying to get said prototypes from the PC's.

Yup, this has so many implications. Of course, you can completely ignore any of these possibilities. To me, it seems more realistic, but you can play it however you wish. I just had to put thses ideas down, as I think they are very intereseting, to say the least.

I hope this helped some.
sabrewolf
11-27-05, 11:55 AM Here are some things to consider, too. A spell, like produce flame, does it thing once. A pistol can do its thing as many times as you pull the trigger.
Just to clarify my former words.. As far as i remember (i might be wrong) Produce FLame creates a temporary effect that besides replicating Light it´s flame can be hurled as a fire bolt once per turn for 1d6 of fire damage.. my base on it was for a continuous iten (unlimited uses, thus no ammo limit).. for a magical weapon is fine.. Yet, for limited ammo, a check on the Gnome Artificer PrC could lead for some insight, or (something that just sparked in my mind) the base price could be the weapon alone and the ammo clip cost something like a wand/staff with shots=charges...
Scorching Ray is a good example.
I´d say any damage spell could be a good example.. :P just need to find those that better fit your weapon idea..
Also, remember that in real life, the cannon came first, then the rifle, and MUCH later the pistol. ....... Now, the above was due to the need of something like a pistol was very low. After all, there were no "adventurers" running around. However, in a game world, that is very much the difference. I would imagine that rifles of any kind and pistols would be a VERY lucrative business.
Right, the way things are researched will deppends on the world/setting, on what is more in demmand..
Also, in a world where magic exists, one can use magic to produce a more refined piece (smaller, more detailed); to reinforce materials used on constructing the weapon; on fueling it or helping some way.. But i´d advise NEVER to mention the ´Fabricate´ spell (and it´s variants) during campaign or at least during iten planning/creation..
Grizzled Gryphon
11-27-05, 12:43 PM Very good points, Sabrewolf. I am not sure what spell I was thinking of when I read 'produce flame', but I was thinking of an intantaneous effect.

As an aside, is there any thing in the Ebberon setting about magic ammo? I am not saying bullet +1 , or the like, I am talking about a bullet that casts Fireball when it is fired, or the like? I would imagine that that isn't allowed, as the abuse that could lead to is rather nasty. Gunny, the fighter has his twin revolvers, and various feats to go along with them. He has, two weapon fighting, and rapid shot, and other feats that deal with ranged attacks. If Gunney puts Bullets of Fireball in all twelve cylinders, and uses rapid shot, he is putting out 4 to 12 fireball spells in one round. :bigeyes: That might be a little over powered. However, I don't have the Ebberon books, so I don't know what feats can be applied to firearms, or if this idea even exists.

Now, if I had a player with a pistol, and he told me that he was going to use Beads of Force for bullets, I know exactly what I would have happen... :evillaugh "sure, sure, go right ahead and do just that, my friend" said the evil Dungeon Master, with a sadistic look in his eye...
sabrewolf
11-27-05, 04:00 PM Now, if I had a player with a pistol, and he told me that he was going to use Beads of Force for bullets, I know exactly what I would have happen... :evillaugh "sure, sure, go right ahead and do just that, my friend" said the evil Dungeon Master, with a sadistic look in his eye...
:evillaugh :evillaugh :evillaugh :evillaugh :evillaugh :devil: Perfect.. just.. Loved the mental picture.. :devil: :evillaugh :evillaugh :evillaugh :evillaugh :evillaugh

As for the fireball-bullets.. i might allow it.. as long as the fellow spend his turns/standard actions to activate each... Though since the fireball-beads have a distinct trait uppon impact allike the beads of force.... :plotting:

But your point is valid, magical bulets might lead to a certain abuse, but it might be balanced by the need of activation, wasting an action for each and single bullet... of course it might be abused also with the first round/clip being left on untill fired.. If even the opening attacks can be an abuse, one might consider (if magical bullets are allowed) to consider two things: 1- the effects of firing the weapon uppon the magical bullet and 2- magic might decay/go unstable while activated and "readyed" bullets might detonate before time...

Post/Author/DateTime	Post
Limit 11-25-05, 12:46 AM	I'm about to start a new campaign and I have decided to allow the renaissance weapons from page 145 in the DMG. One of my players asked about the revolver which is currently listed as a modern weapon and not allowed, but I think it'd be cool that over time, players could invent new fire arms. I mean, its not really a stretch for me to look at a repeating crossbow and want my gun to do the same thing. So any thoughts on rules for inventing new weapons and possibly armor? I imagine that it would take a number of attempts, so it'd probably be a high DC that lower level characters couldn't pull off. But if a character dedicated themselves to it, they'd win eventually. I'd also like any thoughts you folks have on making guns with mishaps. Perhaps an invention check that only fails by five or less has a chance of the gun exploding later. If there any rules for this type of thing in the existing books, please point me in their direction too :-)
Gilean 11-25-05, 08:30 AM	Inventing new spells in DMG can be used as a start. Require a new feat or skill focus to pull it off. It ought to take a lot of time and effort.
Limit 11-26-05, 01:12 PM	Inventing new spells in DMG can be used as a start. That is a good place to start, but I'm not sure how to determine a "level" for technology. Researching an original spell takes one week per spell level and costs 1,000 gold per week. At the end, you make a spellcraft check DC 10 + spell level. I suppose I could base the level on something like average damage. A revolver does 2d8 points of damage, so it's level would be 9? Change the spellcraft check to blacksmithing and then it'd take 9 weeks, 9,000 gold, and a DC 19 check to craft. That wouldn't make it too hard to invent something like the laser rifle though, which does 3d8, making it a level 13.5 weapon. I could also make some sort of chart and just assign a different level to the weapons in the DMG base on my opinion of how powerful they are. Any other thoughts or suggestions?
Lokiyn 11-27-05, 03:09 AM	Try setting Dc checks per week, every month with 4 successful checks advances your characters "tech level" by a set amount, (say a year) or to the next tech milestone (i'm sure there is a timeline out there somewhere you can use. Or something similar.
sabrewolf 11-27-05, 09:50 AM	Inventing new spells in DMG can be used as a start. That is a good place to start, but I'm not sure how to determine a "level" for technology. <cut> Any other thoughts or suggestions? To me, that bit and magical iten creation will posibly be your guidelines. Plus some lateral thinking and flavour to taste.. ;) I´m planning fluff for a side-plot based on X-com: TFtD :evillaugh wich requires ´technology´.. except i´m in fact using techno-magery, I.E. magical itens that a commoner can operate after some training, not needing being a spellcaster.. Researching an original spell takes one week per spell level and costs 1,000 gold per week. At the end, you make a spellcraft check DC 10 + spell level. I suppose I could base the level on something like average damage. That can be used for research before the iten itself can be built. Itens on the same tech branch but piled crescent on the tree (say for example: a pistol, a rifle, a bigger rifle, a stationary cannon, a ship-mounted cannon) could have an ad-hoc to decrease the research time and price as you go up the tree. That wouldn't make it too hard to invent something like the laser rifle though, which does 3d8.... To me, Itens are not much hard to create. New spells are.. But beter then just saying, why not put an example: My Sonic Disruptor sequence: (it´d still in construction but these are the thoughts i´m basing myself of) - Sonic Pistol: Similar to a hand-crosbow. Base spell "Produce Flame". Damge changed to Sonic ( i know one might say sonics are uncommon and an ad-hoc should be applyed, like Sl+1, but since it´s just an example i´ll keep it as is: also guns could deal fire damage as the unchanged spell). Range.. i cant remember and i´m not with my books right now, but if the spell´s reange increment is not enough, consider range enhancing metamagic into calculating or state all eapons have X range increment. Basing on that, and considering the first base pistol to start, it´d be. Produce Flame > lvl 1 spell... Sonic Tech > Pistol weapon: Range: As spell. Rate of Fire: 1 Damage: 1d (sonic) Research Cost = 1,000 gold Research Time = 1 week, Assembly Cost = 2,000 gold (i´d only halve the cost after a few was made or the tech was better underestood.. but you can make it 1k gold if wished) Assembly Time = 2 days or, Assembly Time = Crafting Rules, dependant on check rolls Vs Iten Cost. (i´d use that ´less one actually pull off and build a factory :P ) From that, i decided that the rifle and cannon would have 3d and 5d of damage. To that i can either think on the Empower Spell feat (not much likely) or compare with 2nd or 3rd level spells (or higher). I´d add up the damage dices for repeating weapons for claculation and use the Split Ray metamagic feat to actually give it many shots/round.. Mounted Weaponry or Seige / Ship Weapons would both need range improovements and get a x4 multiplyer for each size category as per normal magic iten creation (with at least 1 since it begins as a large device) Mishaps: These are funny.. I guess the Gnome Artificer have some ruling about that, might be worth checking.. An idea could be a 5% chance per damage die with mishap damage = normal damage (1 shot or full shots) rolled on finished building and/or at each natural 1.. Wonder if that´s of use for you... As for a laser weapon.. :plotting: :mage: :evillaugh "Searing Light" work well for it.. Use the Split Ray Feat for a repeating gun.. or... the Split Ray, Empower Spell, Twined Spell, Repeating Spell supper combo :devil: for a highly expensive but insanely destructive laser gatling maddness..
Gilean 11-27-05, 10:22 AM	Cannons are not that hard to do. A tube with something giving a push when it is burned, that's how the simplest ones worked. Not hard once blackpowder or something similar is found.
Grizzled Gryphon 11-27-05, 11:02 AM	Here are some things to consider, too. A spell, like produce flame, does it thing once. A pistol can do its thing as many times as you pull the trigger. So, maybe consider the damage as a means fo figuring out the equivelent "spell level" should be based on all the damage it can deal. Not over a year, or something, but how much damage it can do before reloading. Now, it is more like a damage over time spell, like Firewall, but you still want to add to it because unlike Firewall, you can decide when that damage is applied. Scorching Ray is a good example. What level do you have to be to get 6 rays? Find out what the highest level spell you can cast at that level, and you have your level that the pistol is closest to. I would increase the prices above what this implies, though, as any prototypes are HUGELY expensive. This goes in real life as well as in a game. For example, the prototype of the Ford Escort cost around 2 million. how much does the production version cost? I believe they started at around 12,000, back when they first came out. At any rate, you get the idea. Also, remember that in real life, the cannon came first, then the rifle, and MUCH later the pistol. Sure, the first black powder weapon wa a little pot with an arrow sticking out of it, but after that came a mortat, then a cannon. The musket followed very closely after that, and then came the pisotl some time later. Just something to think about. Now, the above was due to the need of something like a pistol was very low. After all, there were no "adventurers" running around. However, in a game world, that is very much the difference. I would imagine that rifles of any kind and pistols would be a VERY lucrative business. And, like any other business, whoever makes the best, makes the most money. And everyone knows, adventurers have LOTS of money. I could only imagine that there would be several "companies" trying for the best weapon that an adventurer could want. And, oh, the adventure hooks that leads too!! Rogues working for those companies trying to steal the PC's design, or the companies fighting for the rights to it, or the PC's getting hired to steal the designs of a rival company... wow, it is Shadowrun and D&D mixed together!! See? Guns ARE bad!! LOL. Of course, another possibility, one company wants some of its prototype guns feild tested. Enter the PC's. This can add some interesting twists to any game. While doing some other adventure, the party has to also contend with agents of other companies trying to get said prototypes from the PC's. Yup, this has so many implications. Of course, you can completely ignore any of these possibilities. To me, it seems more realistic, but you can play it however you wish. I just had to put thses ideas down, as I think they are very intereseting, to say the least. I hope this helped some.
sabrewolf 11-27-05, 11:55 AM	Here are some things to consider, too. A spell, like produce flame, does it thing once. A pistol can do its thing as many times as you pull the trigger. Just to clarify my former words.. As far as i remember (i might be wrong) Produce FLame creates a temporary effect that besides replicating Light it´s flame can be hurled as a fire bolt once per turn for 1d6 of fire damage.. my base on it was for a continuous iten (unlimited uses, thus no ammo limit).. for a magical weapon is fine.. Yet, for limited ammo, a check on the Gnome Artificer PrC could lead for some insight, or (something that just sparked in my mind) the base price could be the weapon alone and the ammo clip cost something like a wand/staff with shots=charges... Scorching Ray is a good example. I´d say any damage spell could be a good example.. :P just need to find those that better fit your weapon idea.. Also, remember that in real life, the cannon came first, then the rifle, and MUCH later the pistol. ....... Now, the above was due to the need of something like a pistol was very low. After all, there were no "adventurers" running around. However, in a game world, that is very much the difference. I would imagine that rifles of any kind and pistols would be a VERY lucrative business. Right, the way things are researched will deppends on the world/setting, on what is more in demmand.. Also, in a world where magic exists, one can use magic to produce a more refined piece (smaller, more detailed); to reinforce materials used on constructing the weapon; on fueling it or helping some way.. But i´d advise NEVER to mention the ´Fabricate´ spell (and it´s variants) during campaign or at least during iten planning/creation..
Grizzled Gryphon 11-27-05, 12:43 PM	Very good points, Sabrewolf. I am not sure what spell I was thinking of when I read 'produce flame', but I was thinking of an intantaneous effect. As an aside, is there any thing in the Ebberon setting about magic ammo? I am not saying bullet +1 , or the like, I am talking about a bullet that casts Fireball when it is fired, or the like? I would imagine that that isn't allowed, as the abuse that could lead to is rather nasty. Gunny, the fighter has his twin revolvers, and various feats to go along with them. He has, two weapon fighting, and rapid shot, and other feats that deal with ranged attacks. If Gunney puts Bullets of Fireball in all twelve cylinders, and uses rapid shot, he is putting out 4 to 12 fireball spells in one round. :bigeyes: That might be a little over powered. However, I don't have the Ebberon books, so I don't know what feats can be applied to firearms, or if this idea even exists. Now, if I had a player with a pistol, and he told me that he was going to use Beads of Force for bullets, I know exactly what I would have happen... :evillaugh "sure, sure, go right ahead and do just that, my friend" said the evil Dungeon Master, with a sadistic look in his eye...
sabrewolf 11-27-05, 04:00 PM	Now, if I had a player with a pistol, and he told me that he was going to use Beads of Force for bullets, I know exactly what I would have happen... :evillaugh "sure, sure, go right ahead and do just that, my friend" said the evil Dungeon Master, with a sadistic look in his eye... :evillaugh :evillaugh :evillaugh :evillaugh :evillaugh :devil: Perfect.. just.. Loved the mental picture.. :devil: :evillaugh :evillaugh :evillaugh :evillaugh :evillaugh As for the fireball-bullets.. i might allow it.. as long as the fellow spend his turns/standard actions to activate each... Though since the fireball-beads have a distinct trait uppon impact allike the beads of force.... :plotting: But your point is valid, magical bulets might lead to a certain abuse, but it might be balanced by the need of activation, wasting an action for each and single bullet... of course it might be abused also with the first round/clip being left on untill fired.. If even the opening attacks can be an abuse, one might consider (if magical bullets are allowed) to consider two things: 1- the effects of firing the weapon uppon the magical bullet and 2- magic might decay/go unstable while activated and "readyed" bullets might detonate before time...