I have an idea for my combat system. I posted it over at rpg.net and it seemed to stand up to early comments, so I thought I'd also post here for some more perpsectives....

Two equally-level-matched opponents enter the fray. They each have some initiative value determining who 'goes first'. If you have the initiative on someone else, you get a +1 bonus.

When you attack someone, you could both get hurt. You both roll a dice pool according to your abilities. For example, a fighter character with a sword and light armour who is pretty good might roll 3d6 + 2, plus another one if they have the initiative.

Whoever loses takes the difference in damage.

Lower-level NPC opponents take the average in order to speed up the combat, but every NPC party always has one 'leader' who rolls every test opposed.

Character ability determines the number of dice
Weapon type determines the number of sides per die
Weapon reach, initiative and armor provide simple +1 modifiers to the total

Better armor isn't just a health buffer. Armor allows you to fight more confidently, be more aggressive and less defensive, and so contributes to your ability to inflict damage through increased general combat effectiveness.

This approach will mean that instead of taking turns at throwing 'free punches' at eachother, a combatant will need to consider seriously the chance of suffering damage against a superior opponent.

My only concern is that this requires too much maths at game time. It seems very simple, but are people happy to work out the difference in rolls between two dice pools and apply the difference as damage?

Thanks,
-Tennessee

Hm, not my type of mechanics, i prefer it far simpler, but i'll try to give a valid response from Your, and the Forge's perspective anyway.
First, if your Damage & Combat System is lethal enough, anyone would prefer to avoid superior opponents.
Second, a well armored character always has it easier to enter combat, at least somwhat. Add that to the first, and there may be no point in adding further to the dice pool for Armor.
All in all, the mechanism seem to work.
Some don't mind some counting, they'd play.
I don't like counting so much during Games, i would not play it(, others here on the Forge would, though, i guess).

Tennesse,
  This looks good. I don't see an issue with math. I have played several games with this much math and they go pretty well actually.

Some ideas regarding math overload:

If you're worried about overloading the players, make the GM do more of the math.

If you're worried about overloading the GM, make the players do more of the math.

If you're worried about mental tracking of numbers, provide worksheets, charts, or just scrap paper where numbers can be jotted down.

Hey Tennessee,

You've got something solid here.  I don't think the math is that big a deal, as long as the number of dice involved doesn't get too high.  What is the functional limit for character abilities? 

It's worth mentioning that your system seems to have little opportunity for an inconclusive exchange.  Even if that happens when the roll is exactly equal, with varying die sizes this will be less and less likely the larger they become, and then modifiers will make the erffect more pronounced.

That's not necessarily problematic but is something to be aware of.  It's ther kinds of thing that is I think probably more appropriate for a mass melee context than for a one-on-one conflict in purely fiction-consistent terms; at least thats the feel it has for me.  This is noty a criticism though, and it certainly seems viable to me, just beat in mind that you are stating that a combat exchange has the actual or near certainty of someone being injured, regardless of the situation, with all that this implies.

Thanks for the comments on inconclusive exchange. That's true, but I don't really see it as a problem. Something I'm vaguely intending but haven't firmed up is the healing rate. I thought I might allow combatants to heal up to a certain number of health points immediately post-battle (say about 15%). I haven't really firmed up on the details, but 'health' in my system reflects not merely woundedness, but also magically-assisted vigour. Part of the explanation for the high levels of health the PC's can get is their ability to take advantage of magical energy to bolster their vitality. So PCs will have quite a lot of healing options available to them.

Personally, I find it kind of dis-satisfying having to buy up a million health potions, or hang around for weeks healing between adventures, or praying for health at random altars. I'd much rather just have a game-mechanic which allows players to fight on in some reasonable way. I want to figure out the number of fights the players should have in a row, then back-calculate the healing mechanic to allow for that.

When a player hits zero health, it's really just to indicate that their reserves of energy are low. Maybe they're bleeding and battered too, but they haven't lost any limbs yet. I am thinking I might call it vitality to reflect this.

In setting terms, this will be a reflection of the players all having a limited capacity to redirect their magical abilities towards health regeneration (at say a two-for-one cost) plus having a moderate natural healing rate.

If the balance is right, it basically won't matter if the characters take some damage in every combat. I think it could be a workable and normal aspect of the game...

Cheers,
-Tennessee