Tail size - This isn't quite so straightforward, I think. A relsize of 1 would make a very small tail, and small things don't hit very hard. A club-tail the size of a garden lizard's tailtip wouldn't be very dangerous. I'll need some arena tests for this, unless someone wants to volunteer?
I can test this.
I suppose tail size can be assigned to a creature individually, after deciding whether it will get one at all, and if so whether it will get a normal tail, a [GRASP]ing tail, or a [STANCE] tail. If tail relsize is 40% it's torso's relsize or more (800+) then it can realistically have an attack token using the tail as the weapon, or basis for a weapon. The default tail relsize is only 100, which doesn't make much sense for creatures that use it for something other than swatting flies.
Results are in *drumroll*
body part size DOES affect a creature's combat ability.
I tested 10 times with large groups of elephants with their trunk removed and replaced with a nose to prevent wrestling, tusk attack removed, and kicking attack switched to use the tail (leaving them with nothing but the tail, actually). The elephants with a tail relsize of 2000 always won with few or no casualties, and few injuries. Elephants with a tail relsize of 10 always lost, dieing, obviously. The elephants with larger tails also fared better against other creatures than the elephants with smaller tails.
Here are the raw files for the two species.
[CREATURE:TAILELEPHANT_SMALL]
[DESCRIPTION:A huge, hairless mammal, found grazing in grasslands in groups. It eats plants which it lifts up with its long trunk. When angered, it will attack with its long tusks.]
[NAME:TAILelephant SMALL:TAILelephants SMALL:TAILelephant SMALL]
[CASTE_NAME:TAILelephant SMALL:TAILelephants SMALL:TAILelephant SMALL]
[CHILD:10][GENERAL_CHILD_NAME:elephant calf:elephant calves]
[CREATURE_TILE:'E'][COLOR:1:0:0]
[PETVALUE:500]
[PET]
[GRAZER:12] don't have browsing trees yet
[MOUNT_EXOTIC]
[TRAINABLE]
[LARGE_ROAMING]
[BIOME:ANY_TROPICAL_FOREST]
[BIOME:SHRUBLAND_TROPICAL]
[POPULATION_NUMBER:15:30]
[CLUSTER_NUMBER:3:7]
[BENIGN][MEANDERER][NATURAL]
[PREFSTRING:strength]
[BODY:QUADRUPED:TAIL:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:THROAT:NECK:SPINE:BRAIN:SKULL:MOUTH:2TUSKS:GENERIC_TEETH:RIBCAGE]
[BODY_DETAIL_PLAN:STANDARD_MATERIALS]
[USE_MATERIAL_TEMPLATE:IVORY:TOOTH_TEMPLATE]
[STATE_NAME:ALL_SOLID:ivory]
[STATE_ADJ:ALL_SOLID:ivory]
[BODY_DETAIL_PLAN:STANDARD_TISSUES]
[USE_TISSUE_TEMPLATE:IVORY:IVORY_TEMPLATE]
[TISSUE_NAME:ivory:NP]
[BODY_DETAIL_PLAN:VERTEBRATE_TISSUE_LAYERS:SKIN:FAT:MUSCLE:BONE:CARTILAGE]
[SELECT_TISSUE_LAYER:HEART:BY_CATEGORY:HEART]
[PLUS_TISSUE_LAYER:SKIN:BY_CATEGORY:THROAT]
[TL_MAJOR_ARTERIES]
[BODY_DETAIL_PLAN:STANDARD_HEAD_POSITIONS]
[BODY_DETAIL_PLAN:HUMANOID_RIBCAGE_POSITIONS]
[RELSIZE:BY_CATEGORY:TAIL:10]
[USE_MATERIAL_TEMPLATE:SINEW:SINEW_TEMPLATE]
[TENDONS:LOCAL_CREATURE_MAT:SINEW:200]
[LIGAMENTS:LOCAL_CREATURE_MAT:SINEW:200]
[HAS_NERVES]
[USE_MATERIAL_TEMPLATE:BLOOD:BLOOD_TEMPLATE]
[BLOOD:LOCAL_CREATURE_MAT:BLOOD:LIQUID]
[CREATURE_CLASS:GENERAL_POISON]
[GETS_WOUND_INFECTIONS]
[GETS_INFECTIONS_FROM_ROT]
[USE_MATERIAL_TEMPLATE:PUS:PUS_TEMPLATE]
[PUS:LOCAL_CREATURE_MAT:PUS:LIQUID]
[BODY_SIZE:0:0:500000]
[BODY_SIZE:2:0:2500000]
[BODY_SIZE:5:0:5000000]
[BODY_APPEARANCE_MODIFIER:LENGTH:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:HEIGHT:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:BROADNESS:90:95:98:100:102:105:110]
[MAXAGE:50:70]
[ATTACK:KICK:BODYPART:BY_CATEGORY:TAIL]
[ATTACK_SKILL:STANCE_STRIKE]
[ATTACK_VERB:slap:slaps]
[ATTACK_CONTACT_PERC:100]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_WITH]
[DIURNAL]
[HOMEOTHERM:10066]
[SWIMS_INNATE][SWIM_SPEED:2500]
[MUNDANE]
[CASTE:FEMALE]
[FEMALE]
[CASTE:MALE]
[MALE]
[SELECT_CASTE:ALL]
[SET_TL_GROUP:BY_CATEGORY:ALL:SKIN]
[TL_COLOR_MODIFIER:GRAY:1]
[TLCM_NOUN:skin:SINGULAR]
[SET_TL_GROUP:BY_CATEGORY:EYE:EYE]
[TL_COLOR_MODIFIER:IRIS_EYE_BROWN:1:IRIS_EYE_GOLD:1:IRIS_EYE_YELLOW:1]
[TLCM_NOUN:eyes:PLURAL]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:5]
[CREATURE:TAILELEPHANT_LARGE]
[DESCRIPTION:A huge, hairless mammal, found grazing in grasslands in groups. It eats plants which it lifts up with its long trunk. When angered, it will attack with its long tusks.]
[NAME:TAILelephant LARGE:TAILelephants LARGE:TAILelephant LARGE]
[CASTE_NAME:TAILelephant LARGE:TAILelephants LARGE:TAILelephant LARGE]
[CHILD:10][GENERAL_CHILD_NAME:elephant calf:elephant calves]
[CREATURE_TILE:'E'][COLOR:5:0:1]
[PETVALUE:500]
[PET]
[GRAZER:12] don't have browsing trees yet
[MOUNT_EXOTIC]
[TRAINABLE]
[LARGE_ROAMING]
[BIOME:ANY_TROPICAL_FOREST]
[BIOME:SHRUBLAND_TROPICAL]
[POPULATION_NUMBER:15:30]
[CLUSTER_NUMBER:3:7]
[BENIGN][MEANDERER][NATURAL]
[PREFSTRING:strength]
[BODY:QUADRUPED:TAIL:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:THROAT:NECK:SPINE:BRAIN:SKULL:MOUTH:2TUSKS:GENERIC_TEETH:RIBCAGE]
[BODY_DETAIL_PLAN:STANDARD_MATERIALS]
[USE_MATERIAL_TEMPLATE:IVORY:TOOTH_TEMPLATE]
[STATE_NAME:ALL_SOLID:ivory]
[STATE_ADJ:ALL_SOLID:ivory]
[BODY_DETAIL_PLAN:STANDARD_TISSUES]
[USE_TISSUE_TEMPLATE:IVORY:IVORY_TEMPLATE]
[TISSUE_NAME:ivory:NP]
[BODY_DETAIL_PLAN:VERTEBRATE_TISSUE_LAYERS:SKIN:FAT:MUSCLE:BONE:CARTILAGE]
[SELECT_TISSUE_LAYER:HEART:BY_CATEGORY:HEART]
[PLUS_TISSUE_LAYER:SKIN:BY_CATEGORY:THROAT]
[TL_MAJOR_ARTERIES]
[BODY_DETAIL_PLAN:STANDARD_HEAD_POSITIONS]
[BODY_DETAIL_PLAN:HUMANOID_RIBCAGE_POSITIONS]
[RELSIZE:BY_CATEGORY:TAIL:2000]
[USE_MATERIAL_TEMPLATE:SINEW:SINEW_TEMPLATE]
[TENDONS:LOCAL_CREATURE_MAT:SINEW:200]
[LIGAMENTS:LOCAL_CREATURE_MAT:SINEW:200]
[HAS_NERVES]
[USE_MATERIAL_TEMPLATE:BLOOD:BLOOD_TEMPLATE]
[BLOOD:LOCAL_CREATURE_MAT:BLOOD:LIQUID]
[CREATURE_CLASS:GENERAL_POISON]
[GETS_WOUND_INFECTIONS]
[GETS_INFECTIONS_FROM_ROT]
[USE_MATERIAL_TEMPLATE:PUS:PUS_TEMPLATE]
[PUS:LOCAL_CREATURE_MAT:PUS:LIQUID]
[BODY_SIZE:0:0:500000]
[BODY_SIZE:2:0:2500000]
[BODY_SIZE:5:0:5000000]
[BODY_APPEARANCE_MODIFIER:LENGTH:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:HEIGHT:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:BROADNESS:90:95:98:100:102:105:110]
[MAXAGE:50:70]
[ATTACK:KICK:BODYPART:BY_CATEGORY:TAIL]
[ATTACK_SKILL:STANCE_STRIKE]
[ATTACK_VERB:slap:slaps]
[ATTACK_CONTACT_PERC:100]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_WITH]
[DIURNAL]
[HOMEOTHERM:10066]
[SWIMS_INNATE][SWIM_SPEED:2500]
[MUNDANE]
[CASTE:FEMALE]
[FEMALE]
[CASTE:MALE]
[MALE]
[SELECT_CASTE:ALL]
[SET_TL_GROUP:BY_CATEGORY:ALL:SKIN]
[TL_COLOR_MODIFIER:GRAY:1]
[TLCM_NOUN:skin:SINGULAR]
[SET_TL_GROUP:BY_CATEGORY:EYE:EYE]
[TL_COLOR_MODIFIER:IRIS_EYE_BROWN:1:IRIS_EYE_GOLD:1:IRIS_EYE_YELLOW:1]
[TLCM_NOUN:eyes:PLURAL]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:5]
They should appear at the top of the list in arena mode.
Selectively attacking them with a human shows the difference in size doesn't appear to affect my chances to hit that body part. I think the [SMALL] tag has the biggest effect, because parts that have it are nearly always impossible strikes.
This is interesting to me too. if it has this much effect, then part size should always be taken into consideration when creating a creature. Voracious cave crawlers should have massive mouths as described, these elephants should have the [small] tag taken off their ears (elephants have fairly large ears). I would go as far in my modding as making dragons have larger tails and a tail-lashing attack, as that's how I always envisioned them. (I already gave them clawing and kicking attacks to go with the bite, and changed their growth curve to gradually step up to adult size rather than suddenly jump to it after a thousand years.)
I'm going to test how much damage I can do to that part on either animal with blunt, bladed, and stabbing weapons.
Size doesn't seem to directly affect the damage you can do when you strike that part, but it may affect your ability to actually land a damaging blow despite how your chances are described. And it definitively has a real effect on how much damage they can deal with that part... Ow.