Rules
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Permanently under construction

Since starting playing CoC about ten years ago, my friends and I came up with a number of ideas to extend the original rules in order
to provide more realism and detail to play. The combat rules are an important part of our additions and they are intended for experienced
players, although the original rules concepts remain unchanged and after a few sessions you should become quite familiar with the system.
There are many changes and additions we made to other game mechanics, especially the magic system, skill improvement and character
generation. I hope to include them here in the future.
If you have developed your own house rules, too, I would be happy to see them and eventually post them on these pages.

Mail Me !

Weapon Skills
Everyone has a basic rifle and handgun skill of (INT+DEX)/2, so average beginning skills are about 12%. Our house rules say that no
character may increase that skill to more than 60% at character generation. Hit chances are quite good, already, so a player character with
100% handgun skill could easily wipe out entire cults. That would'nt be fun, would it ?
Automatic Weapon skill (AW) starts at 1/2 of rifle skill, but is increased seperately from it (Exception : when your rifle skill is
increased later on and becomes higher than 2 x AW, AW is changed accordingly).
Shotguns are fired with rifle skill, SMGs, automatic rifles and machineguns with AW. There are other skills like Mortar, Cannon
and Flamethrower that start at 0%, but they should be of little use to the average investigator unless you encounter something REALLY big.

Turns
A combat turn lasts about three seconds, while in the original rules it was about five, I think. Where this could make a difference
(e.g. casting time for spells), adjust it accordingly.
Have every player decide on his actions before resolving the turn.
If a character can fire more than one shot in a turn, he will fire the first at his (final) DEX, his second at one-half of his (final) DEX
and so on. If using Rapid Fire with a gun with ROF 1+1 or higher, fire two shots instead every time you can act in the turn.
Example (assuming a DEX of 12 and DEX bonus of +6) :

Hit Points & Hit Locations
When playing according to these rules you should take a moment to modify the statistics for PCs, NPCs and monsters because the damage
and armor values are different from the original rules.

Hit points per location

Damage Bonus

Notes : While a character with (SIZ+CON)/2 of 18 could take twice the damage of someone with a total of 9 in the original rules,
this is no longer true when using these tables.
Monster Hit Points : If you can get your hands on one of those old RuneQuest rulesbooks, it could prove useful for determining non-
human hit locations and hit points because a lot of tables like the one above were included as a playing aid. 

Modify accordingly for non-humanoid targets.

Have a look at the Automobile Combat Table (coming soon) !

Injuries :
The values in the table above mean the hit capacity of the different body parts. If suffering more damage than the location can take,
you are seriously injured. All skills and attributes (except SIZ, INT, APP, EDU) are halved until hit points are brought back to 0.
When the damage in the head or chest adds up to more than twice your capacity, you've met your final fate.

Head             : Roll vs. CON x 3 or become unconscious for 1D20 turns.
Arms/Legs  : Roll vs. CON x 5 or become unconscious. Roll vs. DEX x 5 or drop equipment/fall down. If hit in the leg, unaided
                        walking is impossible.
Chest           : Roll vs. CON x 5 or become unconscious
Abdomen    : Roll vs. CON x 5 or become unconscious. Unaided walking is impossible

Impales :
Impale hits from firearms can only be achieved with bullets and slugs, but not shot. Only head and chest hits can be Impales.
Chances for an Impale are 1/2 of your hit chance when the chest is hit, and 1/5 for head hits.
When an Impale hit is rolled, there is an additional damage equal to the target's unwounded hit capacity in the head/chest.
Example : Don Gino is hit in the chest by a bullet. The hit chance was 48%, the player rolled a 22, so this is an Impale hit.
Don Gino's chest hit capacity is 13 and he has suffered 6 hits by a previous attack. He looses 13 hits plus the usual damage for
the bullet (say, 8 points). His chest hit points are now 13(unwounded) - 6(previous attack) -13(Impale) - 8(bullet) = -14 = stone dead.
This rule is intended to improve the lethality of small caliber guns in the game. Even a single .32 bullet can incapacitate or kill
if it hits the right spot.

Healing Injuries :
Although these rules are grossly unrealistic, they are intended to allow an injured player to rejoin play again soon.
First Aid : One attempt permitted per wound only. If this attempt fails, the player has to rely on natural healing (remember that
doctors are obliged to report bullet injuries to the police). A successful first aid roll restores 1D3 hit points (2D3 with a special success)
and takes about 1D6 minutes to perform. A first aid kit may add +10% to your skill.
Natural healing : Calculate the healing chance for each injured hit location seperately and roll once per day and location to regain 1 hit
point :

A success heals 1 Hit point. A special success (1/5 of your chance) heals 2.
A failed roll indicates no change.
Rolling > 2 x chance means the wound becomes worse : loose 1 hit.
A critical failure costs 2 hits.
Rest & Care means lying in a clean bed most of the day, maybe even having someone prepare your food for you. It does not mean observing
a cult headquarters for six hours during a thunderstorm, while suffering from a broken leg and a bullet in the chest.
Only one character can add his/her bonus for first aid or medicine skill.
EXAMPLE : Harry Jenkins has been hit by a car and suffered 17 hits in the leg (capacity 11), so his leg hit points are at -6 (> Capacity).
He is staying in his hotel room for two days. His CON is 13 and a different investigator with a First Aid skill of 40% cares for him, so he
has a (4 x 13) + 10 = 62% chance per day of regaining 1 hit point in the leg. Rolling 12 or less would mean 2 hits, a critical failure (> 95)
would cost him 2 hits.

Stuns (optional):
Eve if a minor injury will not put a character out of action, the shock and the pain might cause him to be distracted for a moment.
If suffering a wound that costs more than half the capacity in the body part, roll vs. CON x 5 or loose your next full turn. You may
dodge or parry attacks with halved chance or fall prone, but nothing else.

Taking Cover
A good idea. Makes it harder to hit you. Don't reduce hit chances when firing at a partially covered target but instead fire at full
chance and roll for hit location. If the body part hit is behind the cover, the bullet may penetrate the cover and do some damage;
though. Take for example someone leaning around a corner. Only his head, left or right arm and half of his chest should be visible
(unless he is shooting a rifle, in which case the other arm can be hit, too).

Drawing and readying weapons
Drawing a gun from a pocket or holster takes 1/2 of a turn.
Automatic pistols in the 1920's generally were not safe enough to carry them all day loaded and cocked, even with the safety 'ON'.
To reflect this, anyone drawing a pistol must spend an additional half turn readying it. If you prefer to play it risky, the keeper may
on occasion (character falling down a stair, engaging in hand-to-hand combat etc.) request a Luck roll to avoid the gun going off in
your pocket (ouch!).

Firing modes
There are five different modes of fire in these rules : Normal, Rapid, Aimed, Aimed at location and Automatic, influencing the Rate of Fire (ROF), which bonus to use and finally, your chance to hit.
Normal       : Firing reasonably accurate shots. Use Base % and ROF given in the tables.
Rapid          : Sometimes you cannot afford to aim precisely or you don't need to, because your target is so big that you can't miss
                       it anyway. Instead you want to hurt it as badly as you can before being eaten alive. Use Rapid Fire then. Double the
                       number of shots (ROF), but use "Rapid %" bonus instead of "Base %". Note that the difference between Rapid% and
                       Base% increases with calibre, because the gun's blowback becomes stronger with larger calibers, too, making aiming
                       more difficult.
Aimed          : Means that you spend a full turn aiming, then fire at double chance next turn.
A. Location : With every kind of fire you can try to hit a specific hit location. ROF and DEX are not affected; only the chance to hit
                       is halved, but if you achieve a hit, you automatically hit the location you aimed at. If you miss, bad luck. If you want to
                       stop that machete-wielding cultist with the first shot, try aiming at the head. Or use a shotgun.
Automatic   : See page for Automatic Fire. Rather complex. But rather effective, too.
Single-action vs. Double-action : see Hit chances below.

Hit chances
1. Find the appropriate skill on your character sheet
2. Add Base% or Rapid%, depending on if you want to fire precisely or fast. This gives you your Basic Hit Chance (BHC). Note that
    for unskilled shooters, rapid fire can result in negative a hit chance, in which case the chance to hit is 1%. See also note for
    revolvers below. When firing aimed shots using a scope, add 10% to BHC.
3. Determine range to the target. For each gun a Short Range is given. If target is farther than that, BHC is halved (quartered if more
    than double short range and so on). If range to target is 5m (close range) or less, BHC is doubled. The Short Range of rifles is
    multiplied with 1,5 when firing aimed shots using a scope.
4. If you want to aim at a specific location, halve BHC.
5. If target is partially covered, do not reduce the chance, but determine if the cover is hit instead.

There are further modifiers which can affect the final hit chance :
- Bad illumination : The keeper may rule that chances are halved or quartered because of darkness
- Target moving : If the target is moving (running speed at least), halve chances
- Attacker moving : Chances are halved when walking, quartered if running.
- If a character is seriously injured, all skills are halved.
- Of course the keeper can rule that someone who has just suffered a major shock (5 SAN or more) trembles so bad that attack
  chances are decreased (say, halved or quartered).

Some EXAMPLES of hit chances.

Most modern revolvers can be fired single action (SA, cocking the hammer before each shot) or double action (DA, just pulling
the trigger). The difference lies in the ROF and Base%. For DA, use Base% and ROF in brackets. ROF is higher for DA, but the
stronger pull on the trigger will make it more difficult to keep a steady aim.

Scopes and silencers
Silencers aren't of much use when firing ammunition of supersonic speed such as 9mm Para, but are available for .45 ACP
and most of the smaller calibers (.38, .22). They decrease DEX bouns by 1.
I don't know much about US weapon laws in the 1920's, but I assume that in most states it was not permitted to own one
without permit (as there is no special need for silencers in self-defense or hunting).
If you happen to know more about that issue, please let me know.

Scopes can be mounted on most rifles at a cost of 20$. They decrease DEX by 1 because of higher weight and increase Base%
by +10% and multiply range by x1,5.Higher Base% and range apply when firing Aimed shots only.

Special rules
Please see the footnotes included in the weapon tables for additional rules covering special attributes of some guns.

Examples from the tables :

The Colt M1903 is a medium-sized automatic pistol, cal. 38 ACP, with a magazine capacity of 7 rounds, plus 1 extra in
the chamber. It has a Base Hit bonus of 0% when using Normal Fire and -15% for Rapid Fire, so it takes some practice to use
this gun effectively. The Damage for .38 ACP is 1D8+2 hits, which is adequate for self-defense, but not much against a
full-sized monster. One might find the Short Range of 12m of advantage compared to only 5 or 7m for smaller pocket-
pistols . ARM is x 1/2, so the target's armor points are halved before applying damage (full-metal-jacket ammo). The
Dex-modifier is +6, so even if your DEX is below average, you will probably fire before somebody armed with a knife
(Dex +0) can stab you. Jam-number is 99, which means the Colt is a quite reliable gun. Conc is -20, meaning it does not
make too large a bulge under your tuxedo. A/L stands for Automatically available in the US, whilst in Europe a Luck roll
is needed to obtain one of those.

The Winchester M1897 is your classic, no-nonsense pumpgun. Thanks to the Base Hit% of +20 it takes no great skill to
hit somebody with a shotgun. Even with a basic skill (ca. 15%), at close range (chance doubled) the hit chance is 60%. DAM
is 5D6 for an average of 18 hits so you don't have to worry about not stopping the targets if you hit him once. The only drawback
is the slow ROF. You can fire once per turn, or twice if using Rapid Fire, but then all shots are at -15% instead of +20%. A Range
of "40-100" means a Short range of 40m and a maximum range of 100m. There is no Conc value given because it is hard to
imagine how you can conceal a full-length shotgun under your clothes.

Finally, the Thompson M1921 is what every trigger-happy investigator dreams of. A .45 submachinegun made famous by
countless gangster movies, it is usually loaded with 50-round drums.Its high ROF means you can fire 3 shots in Normal Fire,
6 in Rapid Fire or 40 (10x4) in Automatic Fire. Short Range is 30m compared to 12m for .45 pistols since the barrel is much
longer. The 100-round-drums are rare and not very reliable. No Conc and A/E numbers are given, of course. Instead, the "2D4"
entry means the number of bullets that hit the target for each successful burst attack.

Model         : The weapon's common name
Ammo         : The calibre of the gun.
Mag             : The number of shots in the weapon. "+1" means the gun can hold an additional round in the chamber.
                        (M) Magazine, (D) Drum, (B) Belt, (C) Clip-fed (Non-detachable magazine)
Base %      : Your basic hit chance. Add this number to your skill when using normal fire. Where two numbers are given
                        (e.g. C 96), the second number stands for the gun with stock attached. Note the difference between single
                        action and double action fire for revolvers. "1(+1)" means you can fire twice when firing double action, but
                        in that case you will fire at the lower Base% number in brackets.
Rapid %   : The rapid fire hit chance. Add this number to your skill when using rapid fire. Where two numbers are given
                        (e.g. C 96S), the second number stands for the gun with stock attached. For automatic weapons the number in
                        bracket means the bonus for every salvo you fire (beginning with the first).
Ld.                : # of turns it takes to reload the gun. Note that the Flintlock Musket (Brown Bess or similar), the Tromblon and the
                        Colt Dragoon take quite a lot of time to reload because Musket & Tromblon are loaded with loose powder, whilst the
                       Colt is loaded with paper cartridges and percussion caps.
Damage     : Damage inflicted per hit. For shotguns two values are given : DAM in short range, DAM in up to max. range.
                       Shotguns do not impale:
ROF           : # of shots per turn when using normal fire. Double that number when using Rapid Fire. Aimed shots are always at ROF 1.
                      For automatic weapons two values are given (ROF S/A) : the first for firing single shots using Normal or Rapid fire, the
                      second for automatic fire (number of salvoes x shots per salvo).
Range        : Short range of the gun. Medium range is 2x Short,1/2 hit chance; Long is 4x Short, 1/4 chance, Extreme
                      is 8x Short,1/8 chance etc.Although there is no maximum range for most guns, the Keeper may rule that you
                      simply can't see your target beyond a given range. For shotguns, first # is short range, second # is maximum range.
Arm           : Armor multiplier. Multiply target's armor with this and subtract from rolled damage. The high Armor Multiplier
                       for shotguns (x 1,5) means that the pumpgun's not your weapon of choice when fighting monsters that have lot of
                       armor (Remember to change monster stats when applying these rules ! I would  multiply armor values by 1,5 at least).
Dex            : Bonus on DEX-attribute when determining the order in which attacks take place. Note that nearly all pistols of this era
                      could not be carried safely with a round in the chamber so it takes half a turn to ready them after drawing. This is one reason
                      why revolvers were still so popular then.
Jam            : Jam Number. Gun malfunctions when attack roll is equal or higher than this number. To unjam a gun spend
                     a full turn and roll vs. appropriate weapon skill (handgun, rifle) without any bonus. Note : for the P08 Art., MP 18I and
                     the Tommygun two numbers are given. The second one refers to the larger magazine.
# of Hits  : (Automatic Weapons only) The number of rounds that hit the target per successful burst attack, regardless of the number
                     of shots fired. Cannot exceed the number of shots in the burst, of course.
Conc.         : Concealment. Think of this number as a measure of the gun's bulkyness. Can be used as a bonus/malus on spot hidden rolls
                      when trying to figure out whether somebody is carrying a concealed gun.
A/E            : The gun's availability in America/Europe. (A) Automatic - You can buy this gun in most gunshops here.
                      (L) Luck roll - Spend some time (a day at least) and roll vs. Luck to obtain one.
                      (#/#) Uncommon here - Roll vs. Luck divided by this #.
Nation       : The country where the gun is manufactured and/or used by official forces. (A) Army, (P) Police, (N) Navy
Price         : The common price for a new gun. Note that guns uncommon in the area may be difficult to obtain and could cost a lot more
                      than the value given here. See "A/E".

Notes on Heavy Weapons :
Mortars, field guns, hand grenades etc. are listed here mostly for the sake of completeness. Since an Investigator with a heavy MG can
possibly deal with a threat that otherwise would easily obliterate an entire player group before breakfast, you should take care to keep
those toys out of your campaign. Maybe some NPCs from government forces (National Guard, Coast Guard,...) can play a role in your
scenario using some heavier calibers, but don't let your players rely on brute firepower alone.
CoC is not a wargame but a game of suspense and role-playing. Although a little shoot-out every now and then doesn't hurt (haha), a
.38 revolver and a pumpgun should do the job in most scenarios. And the old gamemaster wisdom still holds true : if your players want
too much gunplay, give it to them. After having been on the wrong side of a machinegun once, they should get the idea. And, of course,
there are some things between heaven and earth that give a damn about being shot.

Damage : The damage an object/creature takes when suffering a direct hit by the projectile. (E) means the explosive damage applied to
                 anything in the explosion radius.

Radius :

IF : Indirect Fire

Bibliography :

GURPS Hi-Tech : From Blunderbuss to Bazooka (Steve Jackson Games) contains a wealth of information about things to
make other people unhappy with. It describes the development of firearms from its beginning in the 13th century to modern times, as well
as giving an overview of general technology at the time (means of transportation, surveillance, body armor etc.). Flintlocks, howitzers,
AT-Rockets, silencers, applying shaped charges to breach walls, ammunition reliabilty, it's all there. See also the list on Victorian Firearms.