Basic Land Cannons: Classic and OSR

Basic Land Cannons
Threw together some basic cannon rules for a bit of fun carnage.

First up: I'm keeping it simple.
Cannons are complicated; there are many different types and designs over the centuries. Ammunition sizes vary greatly depending on the size of the cannon and its purpose. Even the name cannon does not apply to what we generally call 'cannons.' Culverins, demi-culverins, demi-cannons, guns, etc. That's more than I want to get into so I'm keeping it simple for these land cannon rules. Galloper, field, and siege.

Galloper
Lighter artillery guns firing smaller shells they were designed to be pulled by a single horse in front of  the gun and carriage with the intention of keeping pace with fast troops and possiblly cavalry. This was often not the case as gun crews were still on foot and the ammunition trundled along behind in ox-carts. This category can also represent small swivel guns.

Field Cannon
Standard artillery guns used by most nations which were typically sited before a battle and not moved until after. This the the type of gun most people think of on a battlefield with wheels on the sides for easier placement and transport. They were used on ships and fort walls. These guns were often captured as the battles swept across the field and their loss was considered a typical even.

Siege Cannon
Massive guns firing up to 60lb or larger shells. These monstrosities were mostly used to batter down walls.

Cannon Damage, Range Inc., Rate of Fire
Galloper: 2d6x2, 200', 1 shot every 1.5 to 2 minutes
Field: 2d6x5, 300', 1 shot every 1.5 to 2 minutes
Siege 2d6x10, 400', 1 shot every 5 minutes

Ammunition
Round Shot (link)
Standard iron ball.
Rolls 1d4x10' from point of impact. If plowing through ranks of men it does possible damage to everyone or thing in a 5' path along its trajectory. Those in its path may make a saving throw to take half damage. If the save is made by 5 or more the victim takes no damage.

Chain Shot
As above except the damage path increases to 10'.

Canister Shot (link)
Used with Gallopers and Field cannon. A Canister round is a can or other container packed with dozens of musketballs or other projectiles which fires out in a cone like a giant shotgun.

The CS fires a cone a width of 30' per 300' it travels. Every target in its zone must make a Saving throw or take 2d6 damage from the shot. Every 300' past the first increment the target gains a +4 bonus to the Saving throw as the shots spread out. A troop 380' out or example would get a +4 bonus. A target out 670' gets a +8 bonus, etc.

Canister rounds are not designed specifically to penetrate cover. They are best vs masses of troops in open fields or open decks. All cover bonuses are added to the Saving throw of those under cover.

Grapeshot
Similar to Canister Shot this load was primarily (but not always) a naval round using fewer and larger balls, had a much shorter effective range, and was expected to hit targets behind cover. When fired it comes out in a cone with a width of 30' per 100' travelled. Every target in its zone must make a Saving throw with a +2 bonus (fewer balls) or take 2d6 damage from the shot. Every 100' past this the target gains a +4 to their Saving throw.
In addition GS ignores 4 points of cover bonus to the Saving throw.

Improvised Explosives
Simple iron balls with gunpowder and fuse were used as grenades.
Sometimes you really had to kill a bunch of motherf@ckers and roll a lit powderkeg at them.

Fused Grenade
2d6, 10' blast radius.
Roll 1d6
⦁ 1-3 explodes at end of round thrown
⦁ 4-6 explodes on thrower' initiative the next round

Powder Keg
4d6, 15' blast radius.
Each additional keg adds +1d6 to damage and 5' to the radius.

OSR Pirate/Renaissance and Colonial: Ship Combat, Weapons, Armor, Etc

Optional Rules, Weapons, Armor

Multiclassing
Maximum total character levels: 20
Maximum total classes: 3

To gain a new class the character must gain enough experience points to reach a new level in his current class. Once this happens he gains a level of the new desired class. The total levels in both classes are added to find his total character level.

Whichever class has the highest exp requirement to reach the next character level becomes the new required exp for the character to level in either class. There is no restriction on which class he must level in, he can raise either as long as he gains the proper exp to gain a new character level.

For Example:
A 5th level Warrior (Fighting-Man) has trained to become a Sorcerer (Magic User) when he gains 32,000 exp (required to reach Fighting-Man level 6).
He is now a 5th level Warrior/1st level Sorcerer. His total character level is 6.

He switches to the exp requirements of the higher cost Sorcerer. He must now gain 80,000 exp (required to reach Sorcerer level 7) to gain a level of either Warrior  or Sorcerer. If he had not multiclassed he would have reached Warrior level 7 at 64,000 exp.

If the same type of class (divided into the categories of Fighting-Men, Tradesmen, and Mystic) is chosen for the new level the character continues with his normal progression in attack and saving throw. If he had chosen another Fighting-Man class, say Scout, his attack and saving throw would continue as a 6th level Warrior.

If a different type of class is chosen the best of both classes is used.

For Example:
The above 5th level Warrior /1st level Sorcerer would use the 5th level Warrior attack and saving throws. If he were to gain enough levels of Sorcerer to beat his Warrior attack and saves he would then use them. Use the best of both.

The character can use any weapon his classes allow but he must follow the armor restrictions for class abilities:
Leather armor or less if the Burglar class is chosen, no armor for spells as a Sorcerer, etc.
Shields may be used if a class allows but must be dropped or slung for thieving or magic.

Surprise modifiers, AC bonus, and to Hit bonuses granted by special class abilities do NOT stack.

Fear & Madness

Firearms Rules

Miscellaneous Situation Rules

Ship Combat Rules

FIREARMS, Dmg, Range
Pistols
Pocket Pistol, 1d8, 5'
Belt Pistol, 1d8, 20’
Horse Pistol, 1d10, 20'

Long Arms 
Caliver , 2d8, 30'
Musket, 2d8, 60' 
⦁ Can be loaded with shot. The shot does reduced damage after the first increment.
⦁ Shot: 3d6/2d6/2d6/1d6/1d6, , maximum of five increments, +2 to Hit first range increment
⦁ Birdshot: 3d4/2d4/2d4/1d4/1d4, maximum of five increments, +4 hit first range increment

Fowler, loaded with birdshot as above, 80'
⦁ Fowler's were in general more delicate than muskets and had longer barrels and smaller bores. They were primarily for bird hunting.

Blunderbuss, 20', +4 hit first range increment
⦁ Shot: 4d6/3d6/3d6/2d6/1d6, maximum of five increments
⦁ Fires in a 15' cone targeting everyone in the cone.

Reload
The reload time for these weapons is two rounds. They can be fired on the user's initiative on the third round.

Reloading a muzzle-loading weapon while moving faster than a walk or on a horse moving faster than a walk requires a Dex check with a -4 penalty. It is impossible to reload on a horse in a full gallop. Failure results in the powder and shot being spilled, wasting one reload. If in a racing wagon or a rolling  ship the weapon can be reloaded normally with a straight Dex check.

Range
Firearms have ten range increments, and suffer a  –2 penalty per increment after the first.
Point Blank: Within 10' of a target (5' for derringers) the shooter gains a +4 bonus to hit.

Firearms Vs Armor
Pistols and Longarms are effective vs armor at close range and reduce the effectiveness of the armor's AC bonus. This applies only to that portion of the character's Armor Class that comes from wearing armor and shields; Dexterity bonuses are unaffected as are cover bonuses. The penalty cannot make a character's Armor Class worse than if he was wearing no armor.

Pistols
At the first range increment pistols ignore 3 points of armor, at second pistols ignore 2 points, at third pistols ignore 1 point. Beyond this no armor is ignored.

Longarms
At the first range increment longarms ignore 5 points of armor, at second longarms ignore 3 points, at third longarms 2 points, at fourth longarms ignore 1 point. Beyond this no armor is ignored.

For creatures, if the DM decides that their AC includes natural armor, the firearm would ignore it as well. If you're unsure of how much to ignore removing 2 points of creature AC is a good rule of thumb. Remove more if you feel you should.

Misfire on a !d20 Attack Roll
Matchlock Misfire 1-4, on 1d20
Wheellock Misfire 1-3
Snaplock Misfire 1-2

If the attack roll is a misfire, the weapon does not fire. The DM should roll 2d6:
2-3 Explosion
4-7 Fouled barrel
8-12 Hangfire

An explosion inflicts 1d6 damage for pistols/2d6 damage long arms on the character holding the firearm. A Saving throw vs Death reduces the damage dice to 1d4's.
The gun is destroyed.

A fouled barrel ruins the shot and renders the gun useless until carefully cleaned, taking 1d3 x 10 minutes.

A hangfire goes off 1d3 rounds later then it should. If the user keeps the gun lined on target he can make a normal attack when it fires.

Dampness/Wet Weather
In light rain there is a chance of failure to fire.
Matchlock 25%, Wheellock 0%, Snaplock 10%

Medium rain raises the chance.
Matchlock 75%, Wheellock 30%, Snaplock 50%

Heavy rain or immersion in water is an automatic failure for all.

This is rolled each round that the weapon is used under these conditions.
If it does fail to fire due to dampness then the gun must be cleaned and dried to be useable, this takes at least a half hour. Snaplocks and matchlocks cannot be reloaded in the rain.

Fire
If a character takes massive fire damage (such as from a fireball or being thrown into a burning fireplace, etc), the DM will decide on a d6 (typically 1 or 2 but possibly higher if the DM warrants it) if containers containing powder for reloads is breached by the fire. If a breach occurs, the black powder ignites and inflicts 1d2 points of damage on the character for every charge carried.

Double Barrel Firearms  
Double barrelled versions of rifles and pistols can be purchased or commissioned but are very expensive. The design can be side by side barrels with their own igniton systems or a revolving barrel which hs it's own primer pan but is twisted around to the flint and trigger mechanism.

Repairing Firearms
Gunsmithing (Int check)
Characters with a background with firearms can build and repair firearms and make bullet molds.

If the check for building fails, the weapon is damaged, and it explodes the first time it is used, causing damage as above. Any failed repair check indicates that the character breaks something in the firearm being fixed, necessitating two subsequent successful checks to repair it.

BOWS,  Damage, Range, Shots/rnd
Long Bow, 1d8, 100', 1 or 2 at -2 each
Short Bow, 1d6, 50’, 1 or 2 at -2 each

MELEE, Damage, Range
Bayonet, 1d6, -
Brass Knuckles, Gauntlet, Basket Hilt/Knuckle Bow, 1d3, -
Club, 1d4, 10’
Hatchet, 1d6 , 10’
Hook, 1d4 , -
Knife, 1d4, 10’
Long Knife, 1d5, 10'
Spear, 1d6, 20’
Straight razor, 1d3, -
Sword (Cutlass, Rapier, Sabre, etc), 1d8, -
Tomahawk, 1d4 , 20’
War Club, 1d6, 10’
Whip, 1d2, 10’ to 15’ reach
Wood Axe, 1d8,  -

ARMOR
Military/Thick Coat +1
Leather Vest/Jacket, Padded Jacket   +2
Buff Coat +3
Breast Plate (front), Brigandine/Coat of Plates, Mail (Very rarely used)   +4
Breast Plate (full)  +5
Shield/Buckler +1
Helm +4 to head (50% cover)

OSR Pirate/Renaissance and Colonial Classes. Fighting Men

For my players in the upcoming Ravenloft Renaissance Game

The Fighting Men
Archer
Brute
Calvaryman
Musketeer
Pirate (Sailor)
Scout
Swashbuckler
Thug
Warrior

Archer
Ability Requirements: Str 13, Dex 13
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Any
Weapons Permitted: Any but greatly prefer bows and one-handed melee weapons.
Prime Attribute (5% xp bonus) Dex 13+

Bow Expertise
+1 to hit with a bow.
If you are only allowing one shot per round the Archer can attack twice per round with a -2 penalty per shot if he takes both.

Long Shot
Range increment's for bows increases by 50 percent.

Sure Shot
No penalty for unstable platform such as a running horse, chariot, rolling ship deck, etc.

Dead Shot
Level 3: After aiming for one full round the archer receives a +4 bonus to his bowshot the next round. This bonus only applies to the first shot of a round.

Rapid Shot
Level 9: An third bow attack is gained.

Trick Shot
Level 12: Called shot penalties reduced by half.

Brute 
Ability Requirements: Str 15, Con 13
Hit Dice: 1d10 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Any
Weapons Permitted: Any but greatly prefer big damage melee weapons.
Prime Attribute (5% xp bonus) Str 15+

Brawn
A Brute character gains +2 to all melee and unarmed damage rolls (in addition to his normal Strength bonus). He knows where to hurt people and hits like a freight train.

Crusher
Once per day per level the Brute can summon his inner reserves of anger and rage to deliver a brutal strike. With a -2 to the attack roll but doing x2 damage (rolled and modifiers both.) If a natural 20 is rolled the modifier is x3. If he takes more than one attack per round, for example using Follow Through, he can take each attack as a Crusher attack as long as all penalties are applied and he hasn't used all of his daily Crusher attacks. This does not stack with attacks such as Backstab or other damage increasing maneuvers.

Destroyer
At third level the Brute can swing wildly attacking twice per round with a melee weapon with a -2 penalty to each attack. This penalty is in addition to any other attack combinations such as two-weapons and follow through if multi-classed.

Follow Through
At level 3 the Brute can make an additional attack if the first attack is a hit. The extra attack can be against the same opponent or against another foe if the new target is within five feet of the Brute. He can attempt a third attack at level 12 and a fourth at level 20.  If an attack misses the follow through ends, any remaining attacks are lost.

Intimidation
Once per day per level the Brute can intimidate creatures with a total HD equal to his level. Thus a fifth level brute can intimidate up to five HD of creatures. Lowest level HD creatures are affected first. The creatures must be able to see the Brute's display of intimidation to be affected. The creatures are allowed a Saving Throw to avoid this effect. Those that fail suffer a –2 to all attacks on the Brute. Most will flee; only the most determined will stay and fight.

Iron Constitution
Brutes make saving throws against disease and poison with a +4 bonus.

Cavalryman
Hit Dice 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Any
Weapons Permitted: Any but greatly prefer firearms and one-handed melee weapons.
Prime Attribute (5% xp bonus) Dex 13+

Follow Through
At level 3 the Cavalryman can make an additional attack if the first attack is a hit. The extra attack can be against the same opponent or against another foe if the new target is within five feet of the Cavalryman . He can attempt a third attack at level 12 and a fourth at level 20.  If an attack misses the follow through ends, any remaining attacks are lost. The Cavalryman must remain in the same location of combat to get the extra attacks. Charging through an area does not allow this.

Horse Fighter
Calvarymen are familiar with combat on horseback. They receive no penalty for attacks made on horseback and gain a +2 bonus to hit with melee weapons vs infantry troops.
(-2 to a non-cavalryman class rider's attack unless he makes a Ride check at -4 penalty.)
⦁ Reloading a muzzle-loading weapon on horse moving faster than a walk normally requires a Dex check with a -4 penalty. Failure results in the powder and shot being spilled. The Cavalryman can do it with a straight Dex check.

Riding
At levels 1, 3, 6, 9, 12, 15, and 18 the Calvaryman gains a cumulative +1 bonus to his riding checks (Dex) for basic riding maneuvers such as stay mounted while the horse is bucking or upset, calming and controlling the horse, guide it with his knees so the rider can shoot, etc. In addition, the Cavalryman can do the following:
⦁ On Horseback the Calvaryman gains a +1 to AC and can use his Dex bonus increase his mount's AC.
⦁ With a successful check, the Cavalryman can drop along the side of the horse for cover, gaining a +4 cover bonus to his AC. This is considered pretty dishonorable by quite a few.
⦁ With a successful check the Cavalryman can fall from a horse and take half damage (see Riding in Rules Clarifications: Miscellaneous.)
⦁ With a successful check the Cavalryman can coax the horse to leap obstacles and the Cavalryman can hang on while the animal is performing the maneuver.

Weapon Focus
At levels 1, 4, 8, 12, and 20 the Cavalryman may choose a melee weapon type (sword, lance, heavy lance, dagger, spear, etc) and  does damage as if the weapon is one dice code higher. Example: a heavy lance does 1d12, a sword does 1d10, etc. Many will choose lance as a focus weapon,

The Musketeer
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Any
Weapons Permitted: Any but greatly prefer firearms.
Prime Attribute (5% experience bonus): Dexterity 13+.

Firearms Expert
The Musketeer receives a +1 bonus to hit with any firearm. This stacks with aiming and point blank shooting.

Fast Reload
The Musketeer cuts their reload time down by one round. Thus a musket or pistol can be reloaded in one round instead of two.

Firearm Repair
Anyone can attempt to fix malfunctioning or broken firearms and cannon. The Musketeer is better at it due to his familiarity with the weapons. Normally this is an Int check, the Musketeer receives a cumulative +1 bonus to this check at every third level. The repair time is left up to the DM based on how badly the weapon is damaged and available tools and materials to fix.

Sure Shot
No penalty for unstable platform such as a running horse, carriage, rolling ship deck, etc.

Fast Draw
Level 3: The Musketeer can draw, ready, and fire a firearm faster. The receive 0 penalty to their shooting attacks when drawing and shooting a firearm(s) in the same round instead of a -2 penalty.

The Musketeer gains a cumulative +1 bonus initiative when drawing a firearm( a -3 penalty) at 3rd level and at 6th, 9th, 12th, etc.

If group initiative is used the Musketeer still rolls separately.

Deadshot
Level 6: After aiming for one full round the Musketeer receives a +4 bonus to his firearm the next round. This bonus only applies to the first shot of a round.

Double Shot
Level 9: The Musketeer can fire one firearm in each hand for two attacks. If pistol size the weapon has no penalty. If larger than a pistol the penalty is -2 for that weapon.

Trick Shot
Level 12: Called shot penalties reduced by half.

Pirate (Sailor)
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Leather or lighter, shield. Their abilites can only be used in Leather or lighter.
Weapons Permitted: Any but prefer medium and short weapons for ship fighting.
Prime Attribute (5% experience bonus): Constitution 13+.

Brawler
They receive a +1 to hit on melee and unarmed attacks.

Close Quarters Fighting
No penalty for fighting in tight spaces such as in a ship or a tunnel (normal penalty of -2)

Gambling
Life aboard ship can be boring and the Pirates find ways to pass the time. One of their favorites is gambling and are notorious for being skilled at most forms of games and at the art of cheating. At 1st level and at 3rd, 6th, 9th, and 12th the Pirate gains a cumulative +1 bonus to his gambling checks.

Sailing (includes navigating and ship repair)
Intelligence check. The Pirate receives a +1 to this check and an additonal +1 bonus at every third level. This includes the art of steering and keeping the ship running as well as navigating or finding one's position using an Intelligence check with the Sailing bonus included. Bonuses may be given for good charts, maps, etc. When used to repair a successful roll allows x2 the number of ship points to be repaired.

Swimmer
+2 to Swimming (Strength) checks

Thief Abilities
As a pillager the Pirate must be able to sneak aboard ships or camps on the shore or docks. He can Move Silently and Backstab as a Thief of equal level. He can Climb Walls but not as well as a Thief. At first level they climb at 50 percent plus five percent per even level.

Swashbuckler
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Leather or lighter.
Weapons Permitted: Any but prefer one-handed melee. Their usually high Dexterity makes them capable two weapon fighters.
Prime Attribute (5% experience bonus): Dexterity 13+.

Fencer
+1 to hit with medium and light melee blade weapons.

Acrobat
+2 to Dex rolls/Saves involving Dexterity.

Florentine
Can attack with a melee weapon in each hand for two attacks with -2 to hit with each. In addition the Swashbuckler can choose to not take the off-hand attack and defend witih the weapon, gaining him a +1 AC bonus that round as if he had a shield.

Light on the Feet
When wearing leather or lighter armors the Swashbuckler recieves a +2 bonus to their AC.

Quick with a Blade
The Swashbuckler is a Dexterity based fighter. He may use his Dexterity bonus instead of his Strength bonus for melee attacks. Damage bonus is still Strength based.

Scout 
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Chain and shield. May wear heavier but lose special abilities while in the heavier armor. See Climber and Stalker below.
Weapons Permitted: Any but greatly prefer firearms and one-handed melee weapons.
Prime Attribute (5% xp bonus) Dex 13+

Agile Fighter
+1 to AC. This applies in chain armor or lighter.

Alertness
The ability to detect danger. -1 to be surprised on a 1d6.

Backstab
Scouts are capable hunters and once a quarry is found they are adept at attacking from surprise to kill the prey.  +4 to attack. x2 damage. x3 damage at levels 5-8. x4 damage at 9th level. This also includes ranged attacks until the target(s) are aware they are being fired upon.

Climber
As a Thief of equal level. If in chain armor  the chance is at -20 percent.

Runner
The Scout's base movement is 135'/45'.

Stalker
In natural settings the Scout can Move Silently and Hide in Shadows at a base 40 percent plus five percent at every even level. If in chain armor the chance is at -20 percent. In non-natural settings (cities, crypts, etc) the percentages are divided by two (rounded up.)

Survival
The ability to live off of the land and survive, this check is rolled in addition to normal foraging rolls. The DM may modify this check for plentiful or exceptionally harsh terrain. This also includes the ability to track with penalties and bonuses for mud, snow, dry ground, etc at the discretion of the DM. The chance for success is 60 percent at first level plus five percent at every even level.

Thug
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Leather
Weapons Permitted: Any but greatly prefer firearms and one-handed melee weapons.
Prime Attribute (5% xp bonus) Constitution 13+

Backstab
Thugs are dangerous and will often take the opportunity to take an opponent out with a stab or shot in the back. When attacking with surprise, from behind, the Thug gains +4 to hit and inflicts double damage. At levels 5-8, damage is tripled, and from a Thug above level 8 such an attack inflicts quadruple damage.

Brawler
Crime is a rough business for the Thug and he has to know how to lay down a beating now and again. Gains a +1 to attack with all melee attacks.

Criminal Contacts
As he gains skill and reputation the Thug meets a lot of others in the crime business. With a successful Charisma check the Thug may ask one favor of a criminal or underword contact such as a pickpocket, burglar, fence, protitute, etc. The favor will be things not generaly available to the average citizen, usually information or perhaps a use of a special talent. The contact will not endanger himself or his employment and will usually negotiate a payment or favor in return if the favor is difficult or unpleasant.
⦁ The Thug receives a bonus to the Charisma check at higher levels: 3, 6, 9, and 12.
⦁ He may call upon these contacts twice per adventure at first level. He may add an extra time for each bonus to his Charisma check due to higher levels.

Gambling
The Thug often supplements his income with a bit of cards and dice.  At 1st level and at 3rd, 6th, 9th, and 12th the Thug gains a cumulative +1 bonus to his gambling checks.

Thief Skills
Thugs pick up a mix of useful skills in his associations with other criminals. He often needs to get in where he's not supposed to be and be quiet about it.
⦁ Pick Pockets: +20%
⦁ Move Silently: +20%

Warrior
Hit Dice: 1d8 per level up to ninth level.
Hit/Save: Fighter
Armor Permitted: Any
Weapons Permitted: Any
Prime Attribute (5% xp bonus) Strength 13+

+1 to attack with melee weapons.

+1 to AC. The Warrior is skilled at defending himself from attack.

Follow Through
At level 3 the Warrior can make an additional attack if the first attack is a hit. The extra attack can be against the same opponent or against another foe if the new target is within five feet of the Warrior. He can attempt a third attack at level 12 and a fourth at level 20.  If an attack misses the follow through ends, any remaining attacks are lost.

Weapon Focus
At levels 1, 4, 8, 12, and 20 the Warrior may choose one melee weapon type (sword, two-handed sword, dagger, spear, etc) and  does damage as if the weapon is one dice code higher. Example: a short sword does 1d8, a sword does 1d10, etc.

DAVE'S OSR AIR COMBAT

Here is a set of air rules I threw together and tested a while back for my Pulp and WWII game. Seems to work pretty well. As always I'm no expert on actual vehicle stats but after checking out a few resources and other systems I've statted several basic planes. I will likely add more and tweak a few things in the future. 

In a side tangent many Fighter planes were BIG. Look at them compared side to side with  tanks. Tanks had the advantage in Heavy Armor of course. 

For use with my Pilot class or whatever you have of your own creations.

Spot Foe
Normal surprise checks with bonus/penalty.

Initiative
Normal + Dex bonus + Miscellaneous (Pilot class bonus, etc.)
+4 if a Maneuver roll was won the previous round.

Maneuvers
Pilot vs Pilot roll (Dex checks)
Success and highest roll wins. Winner gets a +4 to hit and +4 to Initiative bonus the next round.
Tie equals no bonus.

AC
Vehicle AC + Dex bonus + Faster Plane ( +1/25 mph faster)
Flying defensively (no attack attempt) adds +4 

Hit Modifiers
-4 non-Pilot class
+4 maneuver bonus if gained
Speed bonus to AC
+ linked weapon bonus if applicable

Targeting the Engine or Pilot
-6 to attack the engine or cockpit/crew (due to position and better armor at these locations.)
See Engine/Critical System damage below.

Damage to Aircraft
1. IF aircraft is at half Hp's or less, -4 to Piloting rolls.
2. When at half Hp's or less every damaging hit is a critical hit.
3. A natural 20 is a critical hit.
Roll 1d6. On a 1-4  an engine/critical system hit. On a 5-6  1d3 crew are hit.

Aircraft at 0 Hp or less: roll a 1d6. On a 1 it explodes for 6d6 damage to crew. On a 2 it bursts into flame causing 1d6 per round to crew. On a 3-6 it falls from the sky spiraling down in a trail of smoke and flame and impacting in 1d6+2 rounds. Impact damage is 20d6.

Engine/Critical System
x2 damage. 
The damage done  is the percentage chance on a 1d100  that the plane's performance is impacted. IF this roll is successful drop speed by 1/4 of full speed. 

Each additional hit and rolled percent roll drops the speed by another 1/4 of full speed until the plane reaches 0 speed and falls from the sky.

Stalling
IF a natural 1-5 percent is rolled on any of the engine/critical system percentile rolls the engine stalls and the plane begins to fall from the sky.
The Pilot must make an Int check (+ Pilot bonus) - total engine damage to restart it.
The Pilot has 1d4 +2 rounds to get restart or get out. 

Linked Weapons
Multiple machineguns liked to fire at the same time and same target. Each extra weapon gives a bonus to hit or damage as seen on the chart below. If more than one caliber of weapon is linked choose the highest damage for the base damage.

Airplane Bursts
Maximum three attacks per round, 10 bullets per weapon fired per burst ( unlike five per attack in my regular rules air combat requires more to hit). The pilot can choose to use only one or two bursts to conserve ammo. 

AC Bonus and Air Speed
In a plane vs plane combat the speed AC bonus of a slower flying plane subtracted from the bonus of a faster flying plane. The remainder is added as an AC bonus to the faster plane. (The faster plane is better but doesn't completely overwhelm it as it does a ground target.) A P-51 going all-out vs a Messerschmidt 110 going all- out has a +1 AC bonus (7 -6 = 1.)

When speed is reduced either by choice or damage use the lower speeds bonus. 

 Strafing Run
A soldier on the ground is firing at a P-51 mustang. The AC of the plane receives a +7  bonus as it roars by at over 400 mph bumping its AC up to  20 + the Pilot's Dex bonus.

Unfortunately for the pilot it is harder to hit man-sized targets while you're roaring through at 400+ mph. Using all three Machine Gun attacks per each set of available linked weapons allows the Pilot attack an area 30' wide by a number of feet equal to current airspeed. Everyone in this area is rolled against as possible targets but get a bonus to AC equal to the plane's current airspeed bonus plus a cover bonus if they are under partial or soft cover and the War Master rules they can be hit.

Our soldier above who fired at the P-51 gets a +7 to his AC bonus against the plane and since he is standing behind a brick barricade the War Master gives him a +4 cover bonus for a total of +11 to his AC vs the plane. 

OSR Pirates: Ships, Sailing, and Naval Combat

This played well when I tested it.
No doubt there will be some tinkering along the line. I always tinker. It's an obsession.

I have been tinkering with my own Naval rules for  while. I have at least a dozen different naval rules from incredibly rules light to Rolemaster and GURPS. I've read and digested them all but they aren't quite what I am wanting for my own games. Thus I have tinkered and come up with some ideas, many of them familiar, for a usable light rules system easily compatible with Basic, Labyrinth Lord, Swords & Wizardry, etc.

I'm going for familiar concepts and fun easy to use rules, not a hardcore lesson in minute details of ships, cannon, and life at sea circa the golden age of piracy.

First we'll look at some basic ship types. I am no expert and there were many conflicting sources of ships. I boiled that down to a few recognizable ship types in the Pirate genre.
Roll with it.

Following that is the basic Sailing rules and the actual combat rules with cannon stats, etc.

SHIPS STATISTICS
HP
Just like character hit points.
0 HP or less the ship sinks in 1d10 + 6 rounds.

AC
Armor class to hit the ship. Modified by the Captain's Sailing bonus and Ship Maneuverability bonus. .
Faster ships receive an AC bonus of +1 for every full 10' it is faster.

Maneuverability 
How nimble the ship is. It adds to the ship's AC and to attacks against other ships.

Speed
Basic travel feet per round. This represents an average movement. Windy weather (or lack of) can greatly affect the speed of a ship. (See Wind Conditions, Labyrinth Lord, pg 57.)
Daily movement equals the movement rate x 0.6 in miles per hour.

Turn Rate
Ships cannot just turn on a dime; turning takes time and effort.

Sailing Ships
A turn takes one round to give the order and prep for turn.
To turn ninety degrees takes two rounds past the prep round. (Rounds one and two.)
To turn one hundred eighty degrees takes another two rounds past the ninety degree turn. (Rounds three and four.)
While turning the ship continues to move forward in the direction it is turning.

Auxiliary/Rowing Ships
One round to ninety degrees, two rounds total for one hundred eighty degrees.

Crew
The number of men to operate the ship at full efficiency.
Having less than a full amount of crew can severly effect the operation of the ship. Speed is reduced, Sailing checks receive a negative modifier, the time taken to turn the ship, effect repairs, and load guns increases, and the number of guns in a fight decreases.

Passengers 
How many non-crew (troops, paying passengers, etc) can comfortably be carried. For every passenger space not taken up one ton of cargo may be added.

Cargo
The absolute maximum weight of cargo carried by the ship in tons without causing problems. For every ton of cargo space not used one extra passenger can be comfortably lodged.

Guns
Total number of guns that can be fired and their facing. Broadside is the number on one side of  ship. There is the same number (minus damaged cannon) on the opposite side,.

Auxiliary Ships 

1-Mast Ships 

2-Mast Ships 

3-Mast Ships 

4-Mast Ships 

5-Mast Ships 


SAILING 
The Sailing Check
This is the most important check for the characters running things on the ship. It is a simple Intelligence check with modifiers.
The Pirate (Sailor) class gains a bonus to this check at certain levels. NPC's experienced at life on the sea will certainly be assigned Sailing bonuses by the DM.

For opposed Sailing checks both parties roll an Intelligence check with the Sailing bonus and other bonuses/penalties.

The best roll under Int wins. If both made the check by the same amount then  it is a tie and continues into the next round with no bonus to either.

Navigation
Intelligence +Sailing bonus. +/- chart quality bonuses.
For the most part sailing from one place to the other is pretty straight forward with decent charts and navigating instruments. This is left very open for the DM to add challenges and encounters getting from one place to another. Pirates, creatures, inclement weather, mutiny, etc can all make for a challenging voyage.

Spotting other Ships
Ships on the open sea can be spotted miles away. The higher your elevation above the water the further away you can spot other ships, etc.

Spotting a ship is automatic if the lookouts are paying attention. The distance at which they can be spotted are given below in miles and is adjusted for lighting and weather conditions.

To keep it simple take the base spotter location which shows how far out to water in miles a spotter can see.
Multiply this by Light modifiers  then multiply by Weather modifiers.

For example: A Brigantine's lookout in the crow's nest can see out to 24 miles on a normal day. He is on duty during  a cloudy night  with light rain (24 miles x 0.30 x 0.75) = 5.4 miles maximum to spot another ship.

A ship running with it's lights out may require a surprise check by the lookout at the DM's discretion.

NAVAL COMBAT
Naval Combat Rounds are standard old-school D&D rounds with the following phases:
⦁ Tactical Roll
⦁ Initiative
⦁ Movement
⦁ Attack
⦁ Damage

Tactical Roll 
Opposed Sailing checks.
Winner gets a +2 bonus to Sailing checks for the round. This affects initiative, attacks, flee/pursue, etc. Anything involving the Sailing ability.

Initiative
1d6+ Int Bonus + Sailing bonus (including Tactical bonus if won ) + Ship Maneuver bonus.

Movement
Ships move in reverse order of initiative, so that the winner gets to react to the movements of his opponent.

Every ship has a speed measured in feet which the ship can move per round. This can be modified by daily wind conditions.
(See Wind Conditions, Labyrinth Lord, pg 57.)

Attacking
Roll 1d20 +Sailing bonus + Ship Maneuver bonus + Tactical bonus if won.
If the total is higher than the defending ship's AC then a hit has been scored.

The gunner can attack once for each four guns (a salvo.) A full salvo of four guns grants the gunner a attack bonus of +1. Any left over are fired together as a partial salvo but with no +1 to hit bonus.

If 10 guns were fired in a broadside  there would be three attacks, two full four gun salvos and one partial two gun salvo with no bonus to hit.

Damage is by gun type (culverin or cannons.) See damage below.
Damage for each successful hit is rolled gun type and multiplied by the guns in the salvo.
If a full salvo of culverin hit the damage would be 1d4 x 4. A partial salvo would be multiplied by the lesser number of guns.

Damage
Ship's Guns
Demi-culverin: The smallest of the anti-ship guns , firing a 9-pound shot. Sometimes called a 9-pounder.
Damage: 1d3,  Range: 300'
Culverin: The most common ship’s weapon during this time period, firing an 18-pound shot.
Damage: 1d4, Range: 450'
Demi-cannon: A large-bore weapon firing a 24-pound shot.
Damage: 1d6, Range: 600'
Cannon: The largest of the ship-mounted weapons—a massive gun that fires a 45-pound shot.
Damage: 1d8, Range: 600'

The damage listed is what the guns do to ship hit points. This is multiplied x5 vs normal character hit points. Range has five increments. Each increment past the first has a cumulative -2 penalty to hit.

Reload Time
6 rounds (1 minute) for culverin.
12 rounds (2 minutes) for cannon.

Sinking Ships
At 0 HP or less. the ship sinks in 1d10 + 6 rounds.

Repair
1 ship hit points per 5 men per turn. This task requires full attention, so any crew involved in repair cannot take any other action during a turn repairing a vessel.

For complicated repairs (steering, extensive hull damage, etc as DM sees fit) a foreman must be in charge and must make a Repair check to guide the crew and gain the normal daily repaired ship hit points.

Special Shot
Chainshot
If a critical hit is gained roll a 1d6.
1-5: Sail damage as per critical hit chart.
6: Mast damage as per critical hit chart.

Grapeshot
+2 to hit. No ship damage. If a crit is gained 2d6 crew are hit for normal Cannon damge.

Hot Coals
If a critical hit is gained roll a 1d6.
1-5: Ship fire to enemy as per critical fail chart.
6: Major fire to enemy as per critical fail chart.

Critical Hits
Total attack roll and bonus +5 over AC needed to hit.
With gun fire each crit causes 1d6 crewman to be hit for normal (and usually lethal) gun damage as well as a roll on the critical hit table.

Critical Failure
Natural 1 on the d20 roll.
A roll on the critical failure table must be made.

Critical Hit
1d6 crew are hit for cannon damage (roll normal Gun damage dice x 5) and the attacker rolls on the chart below.
1. 1d6 extra crew are hit for cannon damage.
2. 1d6 guns destroyed.
3. Sail damage!-1 to move, -1 to Maneuver rolls. This stacks each time this is rolled and with mast damage.
4. Hold hit! 1d100 percent of cargo is lost.
5. x2 damage to ship from attack.
6. Pilot hit. -2 to Maneuver rolls for 1d4 rounds in the chaos.
7. 2d6 extra crew are hit for gun damage.
8. Mast hit! 1/2 move, -4 to Maneuver rolls. This stacks each time this is rolled and with sail damage.
9. x3 damage to ship from the attack.
10. Powder magazine hit! 1d6x10 damage to ship from explosion. 3d6 extra crew hit with this damage as well.

Critical Failure
1. Guns malfunction. 1d6 guns are out of the fight until repaired.
2. Ship fire! Ship takes 2d6 damage per round until fire is put out. It takes a minimum of 5 crew members 3 turns to douse it. For every five additional crew members, this time can be reduced by 1 turn to a minimum of 1 turn.
3. Hit allied ship for normal cannon damage. If this is not applicable roll again,.
4. Guns misfire! No shot is fired due to dampness, faulty load, etc. Normal reload to fire next volley.
5. Major fire! Ship takes 4d6 damage per round until fire is put out. It takes a minimum of 5 crew members 3 turns to douse it. For every five additional crew members, this time can be reduced by 1 turn to a minimum of 1 turn.
6. Guns explosion! A gun blows up, possibly destroying those nearby. 1d3 guns are lost.

Boarding  
When two ships wish to board one another, their mutual intent makes the action succeed with no chance of failure. If only one side wishes to board, the attacking side must win an opposed Sailing check (Int check with Sailing and Ship Maneuver bonus) with a -4 penalty to the attacking side.

Normal character combat ensues when the two crews clash. Characters who are boarding another ship suffer a penalty of –2 to attack rolls and armor class.

Once crew members come into contact with one another, combat ensues following the standard combat rules.

Ram
Normal naval attack roll.
A desperate maneuver, if the attacker hits he does 6d6x5 hp damage to the enemy ship but takes half of that damage to his own ship.

Flee/Pursuit
Often a drawn out affair with each ship maneuvering towards favorable currents, manipulating rigging and sail to maximize and compete for the wind, and a variety of other tricks. Pursuits often lasted hours or even days.

Every hour the ships roll opposed Sailing checks (including the Tactical bonus if won ) + Ship's Maneuver bonus. The faster ship also gains a  +1 bonus per 10' for speed faster than the slower ship.
If successful the fleeing ship doubles it's lead on the pursuer.
If successful the pursuing ship cuts the fleeing ships lead by half.
If tied or both fail the distance remains the same.
Eventually the pursuer will catch up to the ship for an attack or will fall so far behind as to give up the chase.