PDA

View Full Version : 3.5 Artillery and Canon rules



tigerusthegreat
2011-01-06, 08:32 PM
Has anyone worked out rules, damage and crit stats for canon and artillery pieces? I am looking to compare my ideas with others to see how far off I am.

Dead_Jester
2011-01-06, 09:39 PM
I tend to treat them as Large or bigger ranged weapons, with an appropriate damage (a small cannon might do 3d6 damage, and bigger ones do more). The aiming is probably like a normal ranged attack with a -2 or 4 for the size of the thing, but bigger guns get to simply roll a d20 -whatever the size and circumstances dictate against the target square's ac (usually 10, more if in cover or at a distance).

I also tend to let people fire different kinds of shots, to create different effects (exploisve rounds explode, doing AoE fire and piercing damage, shotgun-like shots have a cone effect, chainshots gets bonuses to sunder attempts on small objects and can trip like a mega bola, etc).

One thing to remember is that the damage shouldn't be too ridiculous, because no one would realistically engineer a weapon so it deals 10x the amount of damage required to kill someone (unless that someone is a dragon/demon/whatever, and then I am all for getting the biggest gun possible).

ocel
2011-01-06, 09:40 PM
the dm's manual has an equipment list for cannons or muskets, but if your looking for more specific firearms for your game, you can try the d20 modern splat book: D20 Past. However it would be more interesting if there rules for recoil, variable reload times, and ectr.

Dead_Jester
2011-01-06, 09:44 PM
Also, if you are looking for firearm rules, Privateer Press' Iron Kingdom campaign setting and some of the early No Quarter issues had a lot of good stuff.

tigerusthegreat
2011-01-06, 09:51 PM
I tend to treat them as Large or bigger ranged weapons, with an appropriate damage (a small cannon might do 3d6 damage, and bigger ones do more). The aiming is probably like a normal ranged attack with a -2 or 4 for the size of the thing, but bigger guns get to simply roll a d20 -whatever the size and circumstances dictate against the target square's ac (usually 10, more if in cover or at a distance).

I also tend to let people fire different kinds of shots, to create different effects (exploisve rounds explode, doing AoE fire and piercing damage, shotgun-like shots have a cone effect, chainshots gets bonuses to sunder attempts on small objects and can trip like a mega bola, etc).

One thing to remember is that the damage shouldn't be too ridiculous, because no one would realistically engineer a weapon so it deals 10x the amount of damage required to kill someone (unless that someone is a dragon/demon/whatever, and then I am all for getting the biggest gun possible).

Yeah the problem I'm running into is stepping up damage for various gun sizes. I want there to be a noticeable difference between a 32lb cannon and a 9lb cannon. Maybe I'll step up the damage by intervals.

For example, a 9lb cannon would do 3d6 (average damage: 9, enough to deal some damage to a wooden ship, but not to a reinforced one), and maybe a 12 or 18lb cannon would do 3d8 (average damage: 12, more than enough to deal damage to even reinforced wood), with big 42lb guns doing maybe 4d10 damage (average 20).

I'm thinking something along the line of (all with round shot):
"Long" 9lb Cannon (Stern gun Only) 3d6
12lb Cannon 3d8
18lb Cannon 3d10
24lb Cannon 4d6
32lb Cannon 4d8
42lb Cannon 4d10
Carronade 3d6

Not sure how to handle grape or canister. Obviously range would be halved but maybe make both area of effect (cone) dealing reduced damage (maybe half damage) with a reflex save for half damage (or one quarter normal damage). This would represent the wounding quality of this kind of shot, while still allowing it to kill outright (a carronade shot for max damage would still do 9 damage, enough to kill most seamen outright).

Dead_Jester
2011-01-06, 09:54 PM
If this is for a sea campaign, then the old heated shot is a lot of fun ( especially when you manage to make a 3-master's sails start burning). I'd probably just make it deal an additional 2d6 fire damage, with a change to make stuff burn.

tigerusthegreat
2011-01-06, 10:09 PM
If this is for a sea campaign, then the old heated shot is a lot of fun ( especially when you manage to make a 3-master's sails start burning). I'd probably just make it deal an additional 2d6 fire damage, with a change to make stuff burn.

Yeah I'm waiting for my players to suggest stuff like that. Doing this on a ship is very very dangerous though (which is why shore batteries did it historically but not many ships).

Fireballing a ships rigging will probably be a useful tactics, moreso than the "standard" tactic of using chain shot and demasting. That said fireballs tend to start fires, and that's not useful when you try to capture.

Reload times are also something I'm at a loss for. I want to say something like 5-7 rounds (I reduces muskets to 3 rounds and pistols to 1).

Nopraptor
2011-01-07, 08:46 AM
hehehe... seamen, sorry I had to
Anyway I think you have it down right.
one question though, what about shrapnel damage from flying pieces of wood the size of your hand that often killed sailors and stuff?

tigerusthegreat
2011-01-07, 01:32 PM
hehehe... seamen, sorry I had to
Anyway I think you have it down right.
one question though, what about shrapnel damage from flying pieces of wood the size of your hand that often killed sailors and stuff?



Yeah I am not sure how to handle that. Thinking that if the section you are by gets hit you have a d% of getting hit by splinters (d% being the amount of damage done to the section after hardness that round). This would mean that in a heavy bombardment there's.a good chance you will get hit but also allows some survivability for players (realism has to be sacrificed sometimes for playability)

Mecharious
2011-01-07, 01:33 PM
Hmm, now why does this look familiar? :smallsmile:

hamishspence
2011-01-07, 01:35 PM
Stormwrack has stats for cannons.

Dragon 321 has stats for various late Renaissance and early post-Renaissance firearms.

tigerusthegreat
2011-01-11, 03:28 PM
These are the cannon stats and rules I went with (along with a sample ship of the line)

Vital Ship Info

Victoria's Vengeance: 52 Gun Converted "Ship of the Line"
Length: 110ft
Width (Center Beam): 35ft
Deck Layout: 2 gundecks, 1 lower hold

Center of the two gundecks is occupied by the guns (60ft). The remaining 25 ft on either side contains the captain's cabin, galley, and some of the crew sleeping area. The lowest deck is for storage and the rest of the crew living area.

Crew Compliment: 450
Armament: 24 (12 per side) 24lb Cannon (Lower GunDeck)
24 (12 per side) 18lb Cannon (Upper Gundeck)
4 (2 Stern, 2 Fore) "Long" 9lb Cannon (Fore and aft deck)
10 deck carronades (5 per side) on main deck.
3 Masts (Main, fore, and Mizzen)


Statistics: Colossal Vehicle. Seaworthiness: +2 Shiphandling: +2:
Speed: 40-120ft/rnd; 4-12 knots
Overall AC: -3 Section AC: 3* Rigging AC: 1
Hull Sections: 114 (sink 38) Section HP: 80 Hardness: 5
Rigging Sections: 3 Rigging Section HP: 80 Hardness: 0**
*Misses by 6 or less may still hit the ship, they have a 33% chance to fall short (no damage), hit another section, or hit the rigging
**When a rigging section is destroyed that mast is considered destroyed. Destroyed masts are harder to replace than damage rigging, and usually require a port for permanent repairs, though masts can be jury rigged.


Gunpowder Weapons (all rules present)

General Rules:
*Gunpowder Weapons are all treated as Martial Weapons, requiring the Martial Weapon Proficiency feat to avoid a -4 penalty to all attack rolls.
*All Gunpowder Weapons have a misfire chance. Before the attack roll is resolved a % die is rolled. If the % die is less than the misfire chance, the gun misfires, and must be cleaned and unjammed before it can be used again (a roll of 1 along with a misfire causes the weapon to explode, causing 1d6 damage per damage die to everyone within a 5 foot radius).
*Accuracy Modifier: These weapons all have an accuracy modifier. This is to represent the differences in accuracy between a stable rifle shot and an unstable pistol shot. These are usually negative due to the level of technology.
*Critical Hits: Guns are much better at dealing critical hits (shown by there good critical ranges). A character hit by a gun critical hit must roll a d20 reflex save to avoid a bodily injury (note this does not prevent the critical damage).
**Bodily Injury: A random body part is critically injured, causing pain and potential loss of limb. A d20 will save is required to continue acting in spite of the injury. Magical or mundane healing (DC 20) can be used to restore the injured party to activity.
*Reloading: Pistols take 3 full round actions to reload. Muskets require 7 full round actions to reload.
**Feat: Reloading Drill reduces reload times to 1 full round for pistols and 3 full rounds for muskets.
*Weather: Due to the devastating effects of weather on powder and ignition sources, most firearms do not work well during very wet weather (rain and the like).

Pistol

Cost: 250gp
Misfire: 20%
Accuracy: -4
Damage 1d10 Piercing (18-20/x2 critical)
Range: 50ft increment
Weight: 3lb


Musket

Cost: 500gp
Misfire; 20%
Accuracy: -2
Damage: 1d12 Percing (17-20/x2 Critical)
Range: 150ft Incriment
Weight: 10lb


Ammunition and Powder:

Black Powder:
60lb barrel: 1000gp 80lb
15lb Keg:250gp 20llb
2lb Horn: 35gp 2lb
Bullets x 10: 3gp 2lb
*1 oz of black powder is required to propel a bullet. (1lb = 16 oz).
*1lb of black powder is needed for carronade, and cannon up to 18lbs
*2lbs of black powder is needed for 24 and 32lb cannon
*3lbs of black powder is needed for 42lb cannons



Cannons

*Cannons are aimed using the Profession (Siege Engineer) or Profession (Cannoneer) skills. The Profession (Sailor) skill can be used but only applies half of its ranks (this is due to the neccesary cross-training sailors receive. They can competantly operate a gun, but not nearly as well as a trained gunner).
*Cannons can fire up to 10x their range incriment. They suffer from a -2 penalty per range incriment past the first.
*BROADSIDE: a broadside is when several cannon are fired together (typically all the cannon on one side of the ship). The attack roll is made by the Chief Gunner, and used by all cannon involved in the broadside. Setting up a Broadside takes a full round action (cannon firing individually will be able to fire slightly faster, but will not benefit from the Chief Gunner's skill). Broadsides get a +2 bonus to the Profession roll when targetting a specific section of the ship.
*Canister: Stats below are for round or chain shot (+2 damage when targetting rigging, -4 damage vs hull). Canister is a shell filled with musket balls that acts like a shotgun. This type of shot does no damage against hull (but can penetrate destroyed sections to injure crew). It delivers 5d6 damage in a 10ft wide cone. Every range incriment past the first decreases this damage by 1d6, but increases the cone area by 10ft, in addition to the normal -2 accuracy per incriment. (so max damage range is 500ft, where it would deal 1d6 damage in a 50ft wide cone). Reflex save DC: 20 for half damage. The attack roll is to see where the shot is centered (deck AC is the same as rigging).

Ships Guns:

"Long" 9lb Cannon (Aft and Fore gun only) 3d6/x2 300ft range incriment +2 accuracy 1500gp
12lb Cannon 3d8/x2 200ft range incriment +0 accuracy 1500gp
18lb Cannon 3d10/x2 250ft range incriment +2 accuracy 2000gp
24lb Cannon 4d6/x2 250ft range incriment +0 accuracy 2500gp
32lb Cannon 4d8/x2 (Requires 2 gundeck ship) 300ft range incriment +2 accuracy 3000gp
42lb Cannon 4d10/x2 (Requires 2 gundeck ship) 300ft range incriment +0 accuracy 4000gp
Carronade 3d6/(19-20)/x2 100ft range incriment +2 accuracy when firing canister 1000gp



Ship Combat

Simplest way to do this is to divide the ship into sections. Every 5 foot section on "rim" of the ship (both sides and fore and aft) represents a hull section. These hull sections have HP and hardnesses. If the ship is targetted by an attack, a section is chosen at random and damage is dealt to that section. Individual sections can be targetted, but this is harder (higher AC). To sink a ship you have to destroy a certain number of these sections. A section is destroyed when its hp are depleted. Adjacent sections loose 1/2 of their remaining hp when a section is destroyed. These sections can regain 1/2 of the hp lost by the adjacent section being destroyed by being reinforced (take a full round action). Guns located in a destroyed hull section are considered inoperable.
SPLINTERS: Players standing in a section that is damaged have d% chance of receiving a splinter wound (where the % is the total damage the section has received) from flying debris. This roll is made once per round. If you are hit by a splinter you may make a reflex safe (DC: 20, 25, or 30, see below) to avoid taking damage. Splinter size is determined by the hull section's remaining hp. If it is at 50% or more max hp, small (DC: 20 damage: 1d6) splinters are dealt, 25%-50%, medium (DC: 25 damage: 2d6), and under 25% large (DC: 30 damage: 3d6). If you are adjacent to a hull section that is destroyed you are automatically hit by large splinters with no reflex save allowed.
DESTROYED SECTIONS: Destroyed sections decrease adjacent hull sections HP by half, disable any guns in their section, and allow shots that would hit their section to injure crew in line with the section instead.