Got a combat system, any strange exceptions or implications to look out for?

[Vitruviansquid]

So I've been writing a combat system for a new, fairly combat-focused system. Its main inspirations are the computer game "For The King" and Pendragon. I wanted to have the Playground look over said system to catch anything in the system that might not end up working out.



When two sides engage in combat and initiative has been figured out, each player and the GM go down the initiative order declaring who their character is attacking. If your character is attacked in melee, you are not then allowed to declare an attack, because your character would be too occupied defending an attack from the faster opponent. Ranged attacks allow the victim to act as normal, and magic spells can be interrupted if a melee attacker engages the caster or a ranged attacker lands a hit on the attacker. Melee attackers cannot choose to gang up against one opponent until there are no more unoccupied opponents.

Attacks are resolved by the attacker and defender rolling "fighting dice pools." If you roll more successes in your dice pool than your opponent, you get to deal damage. If you succeed on each die in your dice pool, it is considered a critical success and you get to deal damage regardless of whether you succeeded more. If you succeed on the same number of dice as your opponent, you also get to attack. So some example situations include:

Character A rolls 3 out of 4 successes, Character B rolls 2 out of 4 successes, so Character A deals damage and Character B does not.
Character A rolls 3 out of 4 successes, Character B rolls 2 out of 2 successes, so both deal damage because A had more dice and B critically succeeded.

In the event that one character is fighting multiple opponents, that character can only deal damage to opponents who rolled fewer successes than he.

Once it has been determined that you can deal damage, you roll a "damage dice pool" that depends on your character's weapon. Heavier weapons have 5 dice, lighter weapons have 3 dice, and middling weapons have 4 dice. The number of successes in your damage dice pool determines the amount of damage you do on a character's location.

Each character has a table sized to a die type (4, 6, 8, 10, or 20) that is rolled whenever they receive damage, where each number on the table represents a part of their body that can be hit. For example, a player character has a table that looks like:

1. Head - 2
2. Body - 2
3. Heart - 3
4. Arm -2
5. Arm - 2
6. Body - 2
7. Body - 2
8. Body -2
9. Leg - 2
10. Leg -2

When you deal damage over the value to the part of the body hit, it is crippled, resulting in a resulting debuff. For example, getting hit in the arm reduces your rolls on the fighting dice pool. Wearing armor increases the value required to cripple your body part where you are armored. For example, wearing a metal helmet increases your head's number to 4.

A character can be knocked out of the fight if too many body parts of his are crippled, and for humans, this is 3 (but the head and heart count double). Being knocked out and injured has lasting consequences, but players are encouraged to have their characters yield if a fight looks hopeless or to avoid further injury. Characters who have yielded are assumed to have hidden behind more active teammates and can't be attacked further, and are inactive for the rest of combat.

If all characters on a side yield, their side has retreated from combat.

[jok]

Character A rolls 3 out of 4 successes, Character B rolls 2 out of 2 successes, so both deal damage because A had more dice and B critically succeeded.



Would this mean the less skill I have the more critical hits I get? That doesn't seem right.

[Knaight]

When two sides engage in combat and initiative has been figured out, each player and the GM go down the initiative order declaring who their character is attacking. If your character is attacked in melee, you are not then allowed to declare an attack, because your character would be too occupied defending an attack from the faster opponent. Ranged attacks allow the victim to act as normal, and magic spells can be interrupted if a melee attacker engages the caster or a ranged attacker lands a hit on the attacker. Melee attackers cannot choose to gang up against one opponent until there are no more unoccupied opponents.
There's potentially some weirdness in the restriction against ganging up in some situations. Regardless of how slow to react combatants are, they're always fast enough to prevent someone from getting ganged up on through their mere presence. This can make situations like bodyguards get really weird really fast.


Attacks are resolved by the attacker and defender rolling "fighting dice pools." If you roll more successes in your dice pool than your opponent, you get to deal damage. If you succeed on each die in your dice pool, it is considered a critical success and you get to deal damage regardless of whether you succeeded more. If you succeed on the same number of dice as your opponent, you also get to attack. So some example situations include:
Anyone rolling really small dice pools is going to succeed quite frequently guaranteed, particularly in the one die case. It's a bit weird, as is it getting harder to get criticals as you get better.

[Koo Rehtorb]

In the event that one character is fighting multiple opponents, that character can only deal damage to opponents who rolled fewer successes than he.

Does this mean the more people you're fighting the more damage you can potentially do in a round? If you get a good roll vs one guy you stab him. If you get a good roll and you're fighting a crowd of people you could potentially stab all of them?

[Martin Greywolf]

If your character is attacked in melee, you are not then allowed to declare an attack, because your character would be too occupied defending an attack from the faster opponent. Ranged attacks allow the victim to act as normal, and magic spells can be interrupted if a melee attacker engages the caster or a ranged attacker lands a hit on the attacker.


Potentially problematic. First off, what does magic being interrupted mean? If it means that you can't cast if you are engaged that round by anyone in melee regardless of when, you can shut down mages really easily. If it means you can't cast if you are engaged by someone with higher initiative, then your wizards need to pump that stat to remain useful, which is a whole bag of trouble.




Melee attackers cannot choose to gang up against one opponent until there are no more unoccupied opponents.


This is just stupid, to be frank. You can absolutely gang up on a guy even if you're in a shield line vs shield line situation, provided you have long enough weapon. There was this one time when the enemy shield line took an exception to my warhammer and I got dogpiled by five guys with swords (praised be good quality helmets). Reality aside, it also robs you of one of the most important tactical decisions - who to attack.



If your character is attacked in melee, you are not then allowed to declare an attack
...
If you succeed on the same number of dice as your opponent, you also get to attack.


Bad idea - this means that people with lower initiatives almost never get to do any damage. Unless I'm misrepresenting something.



If you succeed on each die in your dice pool, it is considered a critical success and you get to deal damage regardless of whether you succeeded more.


Not only does this have, as others pointed out, the problem of the less good you are the more crits you get, it also means that people with low initiative will WANT small dice pools just to get crits to be able to do damage.



When you deal damage over the value to the part of the body hit, it is crippled, resulting in a resulting debuff. For example, getting hit in the arm reduces your rolls on the fighting dice pool. Wearing armor increases the value required to cripple your body part where you are armored. For example, wearing a metal helmet increases your head's number to 4.


This is a bit too time consuming for my tastes, but to each his own. Where I see a potential issue is that armor or base toughness negates an attack completely if it's high enough. That means you need to really think about what numbers to assign where, because you risk making people literally untouchable otherwise.



1. Head - 2
2. Body - 2
3. Heart - 3
4. Arm -2
5. Arm - 2
6. Body - 2
7. Body - 2
8. Body -2
9. Leg - 2
10. Leg -2


Having head and heart count as double here is redundant, since you already have critical hits, IMO. That aside, you start your numbers at 2, which may or may not be unnecessary, depending on whether anything you have in your world has toughness of 1. Armor increasing this, well, it's a solution that will work, just don't go claiming it's realistic - most places you'd aim for in real combat (joints on the inside and outside, veins, lungs, eyes) aren't there.



A character can be knocked out of the fight if too many body parts of his are crippled, and for humans, this is 3 (but the head and heart count double). Being knocked out and injured has lasting consequences, but players are encouraged to have their characters yield if a fight looks hopeless or to avoid further injury. Characters who have yielded are assumed to have hidden behind more active teammates and can't be attacked further, and are inactive for the rest of combat.

If all characters on a side yield, their side has retreated from combat.

If you want to make a concession mechanic, either give players control over how exactly that happens ("I fall into a ditch and am unnoticed"), or allow the enemy to drag their bodies away if they manage to push their allies back. The way you have this, the players can fight to almost last breath and then be completely safe, a fight like this carries very little actual danger.

Also, can you concede at any time? Like, after attack rolls have been made? Because that needs to be addressed.

[Vitruviansquid]

Would this mean the less skill I have the more critical hits I get? That doesn't seem right.

You do not get extra dice in your dice pool by having less skill. Having less skill would be represented by having a penalty to your rolls on the dice.

The original idea was that you would have around 4 dice in your fighting dice pool, and it would only go down to 3 or up to 6, but I haven't decided what fewer or more dice would represent.

[Vitruviansquid]

There's potentially some weirdness in the restriction against ganging up in some situations. Regardless of how slow to react combatants are, they're always fast enough to prevent someone from getting ganged up on through their mere presence. This can make situations like bodyguards get really weird really fast.


Anyone rolling really small dice pools is going to succeed quite frequently guaranteed, particularly in the one die case. It's a bit weird, as is it getting harder to get criticals as you get better.

There should be a written across-the-board rule that you can't have 1 die in a pool. I'm pondering whether you shouldn't also have 2 dice in a pool either.

The original reason for the rule against ganging up was to eliminate situations where it was more than 1 vs. more than 1. But now that I think about it, it shouldn't be a big problem to allow that, since anyone involved in the melee could deal damage to an opponent with fewer dice and deal damage on critical successes.

[Vitruviansquid]

Does this mean the more people you're fighting the more damage you can potentially do in a round? If you get a good roll vs one guy you stab him. If you get a good roll and you're fighting a crowd of people you could potentially stab all of them?

No. You still have one damage roll, you could simply choose which opponent with a fighting roll lower than you to deal damage to. That was worded confusingly.

[Vitruviansquid]

Potentially problematic. First off, what does magic being interrupted mean? If it means that you can't cast if you are engaged that round by anyone in melee regardless of when, you can shut down mages really easily. If it means you can't cast if you are engaged by someone with higher initiative, then your wizards need to pump that stat to remain useful, which is a whole bag of trouble.




This is just stupid, to be frank. You can absolutely gang up on a guy even if you're in a shield line vs shield line situation, provided you have long enough weapon. There was this one time when the enemy shield line took an exception to my warhammer and I got dogpiled by five guys with swords (praised be good quality helmets). Reality aside, it also robs you of one of the most important tactical decisions - who to attack.



Bad idea - this means that people with lower initiatives almost never get to do any damage. Unless I'm misrepresenting something.



Not only does this have, as others pointed out, the problem of the less good you are the more crits you get, it also means that people with low initiative will WANT small dice pools just to get crits to be able to do damage.



This is a bit too time consuming for my tastes, but to each his own. Where I see a potential issue is that armor or base toughness negates an attack completely if it's high enough. That means you need to really think about what numbers to assign where, because you risk making people literally untouchable otherwise.



Having head and heart count as double here is redundant, since you already have critical hits, IMO. That aside, you start your numbers at 2, which may or may not be unnecessary, depending on whether anything you have in your world has toughness of 1. Armor increasing this, well, it's a solution that will work, just don't go claiming it's realistic - most places you'd aim for in real combat (joints on the inside and outside, veins, lungs, eyes) aren't there.



If you want to make a concession mechanic, either give players control over how exactly that happens ("I fall into a ditch and am unnoticed"), or allow the enemy to drag their bodies away if they manage to push their allies back. The way you have this, the players can fight to almost last breath and then be completely safe, a fight like this carries very little actual danger.

Also, can you concede at any time? Like, after attack rolls have been made? Because that needs to be addressed.

Points I haven't thought about yet in bold.

Wizards aren't a class. Instead, everyone is something like a fighter or archer, and they can optionally get a magic spell or two meant to supplement their fightering or arching. NPCs can be of the squishy wizard archetype. There would also be the availability of different special rules allowing casting under adverse circumstances, like concentration in D&D.

People will lower initiatives can deal damage when they are being attacked back to the person who attacked them, based on them getting more successes on their fighting rolls than their attacker, or getting a critical success. Initiative is also based on a roll rather than set for every round.

Rounds are expected to take much longer to resolve than in D&D, but I also expect there to be fewer rounds. Will have to playtest and maybe push lethality in one way or another to ensure that pacing is fine.

Head and Heart counting for double is because characters don't have hp to deal crit damage to. Crippling a body part *is* dealing damage, but you can only sustain so much crippling until you are out of the combat. I was thinking of making a critical success on the damage dice to mean either a re-roll and add the old result, or an automatic crippling result. (Of course, you don't get fewer damage dice for having less skill, you get fewer damage dice for wielding a lighter weapon).

On concessions, I want yielding to be frequent and conceding the entire fight to be not-unheard-of. I was fooling around with a mechanic to make certain conditions of conceding mean a disorderly retreat where enemies will continue to attack for free for a round, or an covered retreat where enemies will not, based on the current round or the number of characters who yield in a round. I wanted to have rules surrounding concession because concession should be a fairly large part of the game, so it can't be purely based on GM fiat. I should specify when players should declare they concede (probably at the end of a round, before initiative for the next round is rolled).

Thanks for the feedback so far, everyone. Gave me a lot to think about and edit.

[erikun]

Interesting idea. I think I might be able to offer a few suggestions.


When two sides engage in combat and initiative has been figured out, each player and the GM go down the initiative order declaring who their character is attacking. If your character is attacked in melee, you are not then allowed to declare an attack, because your character would be too occupied defending an attack from the faster opponent. Ranged attacks allow the victim to act as normal, and magic spells can be interrupted if a melee attacker engages the caster or a ranged attacker lands a hit on the attacker. Melee attackers cannot choose to gang up against one opponent until there are no more unoccupied opponents.
First, I would remove the restriction against ganging up. For one, several-on-one is going to happen anyways in some fights just through uneven odds and characters being eliminated, so it would be easier to treat this as the standard rather than the exception which always comes up. For two, it results in really strange situations like the almost-dead skinny thief being immune in the middle of the battlefield, because they are busy kicking the wizard in the shins.

Second, allow characters to declare their intended targets, but THEY can be interrupted by someone else intending to attack them. That is, if Bandit A tries to attack the party Wizard (which puts Bandit A and Wizard into combat), then Fighter B can decide to attack the Bandit, putting Bandit A and Fighter B into combat. The Wizard is then free to make their attack on their turn, because they are no longer being attacked by anyone. As such, the "engagements" can switch up while attacks are being declared, and the "fighting dice pools" only come up once all the initiatives have been run though. If someone was attacked during their turn then they don't get to choose an attack, even if they are later freed up.

Third, allow attacking characters (but not defenders) to change their action to a defensive one at any point. That is, if Bandit A was attacking the Wizard and was targetted by the party archer, then they could break off the attack and dodge behind cover. This, again, would make the fight more dynamic, and give resources to characters who are trying to protect vulnerable party members.


Attacks are resolved by the attacker and defender rolling "fighting dice pools." If you roll more successes in your dice pool than your opponent, you get to deal damage. If you succeed on each die in your dice pool, it is considered a critical success and you get to deal damage regardless of whether you succeeded more. If you succeed on the same number of dice as your opponent, you also get to attack.

In the event that one character is fighting multiple opponents, that character can only deal damage to opponents who rolled fewer successes than he.
I would change that last bit to "the opponent who rolled the fewest successes (either one for ties)." If you require less successes, then you could end up with one character rolling 4/4 successes but unable to hit anything because both opponents had larger dice pools.


Once it has been determined that you can deal damage, you roll a "damage dice pool" that depends on your character's weapon. Heavier weapons have 5 dice, lighter weapons have 3 dice, and middling weapons have 4 dice. The number of successes in your damage dice pool determines the amount of damage you do on a character's location.

Each character has a table sized to a die type (4, 6, 8, 10, or 20) that is rolled whenever they receive damage, where each number on the table represents a part of their body that can be hit. For example, a player character has a table that looks like:

1. Head - 2
2. Body - 2
3. Heart - 3
4. Arm -2
5. Arm - 2
6. Body - 2
7. Body - 2
8. Body -2
9. Leg - 2
10. Leg -2

When you deal damage over the value to the part of the body hit, it is crippled, resulting in a resulting debuff. For example, getting hit in the arm reduces your rolls on the fighting dice pool. Wearing armor increases the value required to cripple your body part where you are armored. For example, wearing a metal helmet increases your head's number to 4.
This seems a bit too complicated. Especially if each body part only has 2 Hit Points (literally, being times they can be hit) then rolling 5 dice to determine hits is going to be excessive. You could probably do without rolling dice for weapon "damage", instead delivering a certain value - perhaps 1 Hit in two different locations, or 2 Hits in one location for a big weapon - and just rolling to determine the hit location. Two hits with a "big" weapon in a single location, even with armor, will end up disabling it anyways, so there isn't much point in having more variance than that.


A character can be knocked out of the fight if too many body parts of his are crippled, and for humans, this is 3 (but the head and heart count double). Being knocked out and injured has lasting consequences, but players are encouraged to have their characters yield if a fight looks hopeless or to avoid further injury. Characters who have yielded are assumed to have hidden behind more active teammates and can't be attacked further, and are inactive for the rest of combat.
It seems fairly irrelevant for the head and heart to count for double. After all, they aren't any harder to hit than any other body part. It isn't any easier or more difficult to defend them, and there is no way for a character to target them. It would just be a case of your opponent rolled 1 twice on a die, and so they knocked out your head and that's 66% of your "health".

There are also game systems like Mechwarrior, and perhaps Runequest, which guide hits "inwards" if a particular incapacitated location is rolled for a hit. I'm not sure if that's something you want to use - perhaps in your case, it would be more reasonable for a hit to strike the character's incapacitated arm than go into their body - but it is something to consider.

[Vitruviansquid]

First, I would remove the restriction against ganging up. For one, several-on-one is going to happen anyways in some fights just through uneven odds and characters being eliminated, so it would be easier to treat this as the standard rather than the exception which always comes up. For two, it results in really strange situations like the almost-dead skinny thief being immune in the middle of the battlefield, because they are busy kicking the wizard in the shins.

I dunno. I counted this as a feature, not a problem to me. You could say the almost-dead thief has then managed to escape the clutches of the fighter by being higher on initiative and thus being more agile. And then the Wizard might just lay that thief out with a critical hit anyways.



I would change that last bit to "the opponent who rolled the fewest successes (either one for ties)." If you require less successes, then you could end up with one character rolling 4/4 successes but unable to hit anything because both opponents had larger dice pools.


True. A critical success in a one-on-many fight should allow the one to pick whomever he wants to hit.


This seems a bit too complicated. Especially if each body part only has 2 Hit Points (literally, being times they can be hit) then rolling 5 dice to determine hits is going to be excessive. You could probably do without rolling dice for weapon "damage", instead delivering a certain value - perhaps 1 Hit in two different locations, or 2 Hits in one location for a big weapon - and just rolling to determine the hit location. Two hits with a "big" weapon in a single location, even with armor, will end up disabling it anyways, so there isn't much point in having more variance than that.

Each body part has 2 "hp" because they are human body parts. The body parts system exists so the system can support easy-creation of monsters that are... weirdly shaped. Possibly gigantic. Possibly many-limbed. It's there to allow you to do something like fight a dragon, hurt its wings so it can't fly, hurt its claws so it can't maul you, hurt its throat so it can't breathe fire on you, and get other kinds of context-specific interactions that wouldn't make as much sense if the effects of a hit were based on the attacker rather than the defender (for example, in DnD 4e, you can use your attack that trips people to trip an acid blob).


It seems fairly irrelevant for the head and heart to count for double. After all, they aren't any harder to hit than any other body part. It isn't any easier or more difficult to defend them, and there is no way for a character to target them. It would just be a case of your opponent rolled 1 twice on a die, and so they knocked out your head and that's 66% of your "health".

I hate that I say this because it feels kind of like a bait and switch, but actually, there are already ways to game the body part system. I neglected to mention them because they didn't seem like a part of the "basic" system (which is a few pages long on a word document right now).

There are options a character can take that allows him to do things like:

- Add and subtract to their rolls on which body part to hit
- Add and subtract to enemies' rolls on which body part to hit.
- Hold a certain stance to make some body parts harder to hit at the cost of making other body parts easier to hit.
- Wear magic armor on different locations that give special effects if they're hit in a particular spot.
- Reroll on which body parts they hit
- Hit multiple body parts at once

and so on.

[erikun]

I dunno. I counted this as a feature, not a problem to me. You could say the almost-dead thief has then managed to escape the clutches of the fighter by being higher on initiative and thus being more agile. And then the Wizard might just lay that thief out with a critical hit anyways.
Eh, okay. That's possible in such a system, especially if it is supposed to replicate a King Arthur Pendragon sort of theme with honor, or chivalry, where one-on-one fights are considered the "normal" and so characters would reasonably pursue it when given the choice.

But I do note that most fights, even ones which start out fair, will likely end up unbalanced as characters retreat or get eliminated on each side.


Each body part has 2 "hp" because they are human body parts. The body parts system exists so the system can support easy-creation of monsters that are... weirdly shaped. Possibly gigantic. Possibly many-limbed. It's there to allow you to do something like fight a dragon, hurt its wings so it can't fly, hurt its claws so it can't maul you, hurt its throat so it can't breathe fire on you, and get other kinds of context-specific interactions that wouldn't make as much sense if the effects of a hit were based on the attacker rather than the defender (for example, in DnD 4e, you can use your attack that trips people to trip an acid blob).
You could easily have weapons which deal 3 HP, 5 HP, or even more. A boar spear (https://en.wikipedia.org/wiki/Boar_spear) is an example of a real life weapon where that could apply: those things are large, 7 feet or more, and awkward to wield. But they are designed to kill in a single hit, and so giving it 5 hits of damage or more would certainly be reasonable. Any sort of specialized dragon-slaying pikes are likely to be designed with similar sensibilities in mind.

Although really, part of that recommendation is to eliminate the variables in combat. Already it is a question of initiative, of if the target will be available to be attacked, of being able to deal damage, and of being able to hit the correct spot (or near the correct spot) in order to deal enough damage. Thowing in another variable (dealing anywhere from 0 hits to 5 hits) just seems like it turns things even more arbitrary.


I hate that I say this because it feels kind of like a bait and switch, but actually, there are already ways to game the body part system. I neglected to mention them because they didn't seem like a part of the "basic" system (which is a few pages long on a word document right now).

There are options a character can take that allows him to do things like:

- Add and subtract to their rolls on which body part to hit
- Add and subtract to enemies' rolls on which body part to hit.
- Hold a certain stance to make some body parts harder to hit at the cost of making other body parts easier to hit.
- Wear magic armor on different locations that give special effects if they're hit in a particular spot.
- Reroll on which body parts they hit
- Hit multiple body parts at once

and so on.
That's fine. I'm sure you haven't laid out your entire system yet, so there are going to be details you haven't mentioned.

Also, I might go with the d20 (or even d100) to hit and make certain spots, like the head and heart, a much smaller chance than hitting an arm or the chest. This way, they are less likely to be hit in general, and so their higher value makes more sense. Perhaps even make them more vulnerable, with less HP than something like the chest and legs, could work.

The biggest concern with targetting is that it is either so worthless that it isn't worth the effort (D&D3e puts such a big penalty with such little reward that there is no reason to do it) or it is so effective that it is pointless to ever do anything else. (if you could blind or OHKO with a blow to the head, why attack any other way?) As such, it's fairly tricky to get such a system done right, at least from what I've seen.

Adding/Subtracting number from the to-hit roll is going to result in a lot stranger results than you might think. If, for example, Head requires a 1 on a d20 and Heart requires a 10, then a roll which can be modified two spaces is almost twice as likely to hit the Heart as it is the Head. Only 1, 2, & 3 could hit the Head, while 8, 9, 10, 11, & 12 can hit the Heart. As such, being next to the "edges" of the scale suddenly becomes much more important. That's my biggest concern with that situation, and it would probably require quite a bit of playtesting to find numbers and locations on the scale which work the way you intent it to.

[Vitruviansquid]

Eh, okay. That's possible in such a system, especially if it is supposed to replicate a King Arthur Pendragon sort of theme with honor, or chivalry, where one-on-one fights are considered the "normal" and so characters would reasonably pursue it when given the choice.

But I do note that most fights, even ones which start out fair, will likely end up unbalanced as characters retreat or get eliminated on each side.

True. I wanted a system that was more oriented toward, "Mark your man and take him down" than "Let's all gang up on the biggest threat."


You could easily have weapons which deal 3 HP, 5 HP, or even more. A boar spear (https://en.wikipedia.org/wiki/Boar_spear) is an example of a real life weapon where that could apply: those things are large, 7 feet or more, and awkward to wield. But they are designed to kill in a single hit, and so giving it 5 hits of damage or more would certainly be reasonable. Any sort of specialized dragon-slaying pikes are likely to be designed with similar sensibilities in mind.

Although really, part of that recommendation is to eliminate the variables in combat. Already it is a question of initiative, of if the target will be available to be attacked, of being able to deal damage, and of being able to hit the correct spot (or near the correct spot) in order to deal enough damage. Thowing in another variable (dealing anywhere from 0 hits to 5 hits) just seems like it turns things even more arbitrary.

I'm not sure I see how there is too much arbitrariness in the game (but of course, I have bias).

Many games have a roll for hitting your opponent, and then a roll for dealing damage. We are adding an additional roll to see which body part you hit. The intention is to, outside of perhaps a few specialized monsters, have every kind of hit be meaningful, but have hits on special body parts be extra interesting.


That's fine. I'm sure you haven't laid out your entire system yet, so there are going to be details you haven't mentioned.

Also, I might go with the d20 (or even d100) to hit and make certain spots, like the head and heart, a much smaller chance than hitting an arm or the chest. This way, they are less likely to be hit in general, and so their higher value makes more sense. Perhaps even make them more vulnerable, with less HP than something like the chest and legs, could work.

The biggest concern with targetting is that it is either so worthless that it isn't worth the effort (D&D3e puts such a big penalty with such little reward that there is no reason to do it) or it is so effective that it is pointless to ever do anything else. (if you could blind or OHKO with a blow to the head, why attack any other way?) As such, it's fairly tricky to get such a system done right, at least from what I've seen.

Adding/Subtracting number from the to-hit roll is going to result in a lot stranger results than you might think. If, for example, Head requires a 1 on a d20 and Heart requires a 10, then a roll which can be modified two spaces is almost twice as likely to hit the Heart as it is the Head. Only 1, 2, & 3 could hit the Head, while 8, 9, 10, 11, & 12 can hit the Heart. As such, being next to the "edges" of the scale suddenly becomes much more important. That's my biggest concern with that situation, and it would probably require quite a bit of playtesting to find numbers and locations on the scale which work the way you intent it to.

Interesting note: I actually started the body parts system by representing humans on a D6. I switched to the D10 because I didn't think it would allow enough granularity. There was also a phase when I considered making it a 2d6 to have a bell curve.

Good heads up on the extreme ends of the scale.

Are there any other interactions that would provide some weirdness I could exploit to make the system more interesting?