Combat Mechanics are one aspect of RPGs that generally fascinate me as a player, a GM, and as a game designer. They're often the core conflict resolution system for the RPG, and one of the things that the majority of key sessions in the game will be focused on. They're also one of the crunchiest aspects of most games, and generally one of the few ways that a character will flat out end up dead for failing to succeed at a challenge. Look at three different games, and you'll likely see three different approaches to combat. However none of them are without their flaws, so I wanted to look at some of my favorite features of combat systems, and maybe get you to tell me some of yours.
The normal disclaimer for this type of thing is this: a perfect combat system is impossible to make. All we can do is make a system that better communicates what we want combat to feel like in our game. I'm not trying to knock any combat system here, I'm just trying to point out what I think could make for a good combat system if you put it all together. At least for me, and the games that I want to run.
Simplicity is Key
One of the things a lot of system forget is that you want to try and keep things simple, even in your combat system. For example, Mutants and Masterminds is a fairly simple system. Roll a D20, compare with the DC of the roll, and determine success or failure. However, once in combat you get a whole ton of other things, each with their own special rules. The core mechanic for the system isn't able to handle all the intricacies demanded of it in combat, and so it can become awkward.
The Roll and Keep system (to mention L5R for the first of 2 times) does it a bit better. The core mechanic for L5R allows players to call their own critical successes with something called raises. Now, this transfers great into combat, because when a player wants to try something special (like say, knocking an opponent down, or disarming a sword) if the GM doesn't know the rules for that, they can wing it just by assigning a number of raises. It keeps combat moving smoothly. It also makes the combat system flexible, while still being easy to understand. "How do I flip over him, and then attack?" "You call 2 raises for style of course" works just as well as "How do I hit him as hard as possible?" "put all your raises into damage." The same, simple and repeatedly used mechanic, lets you do it all.
This is one of the things that I really liked about L5R third ed, and was really sad to see go in 3rd ed revised and future editions. Initiative in L5R 3rd ed was fantastic because it was dynamic. This added a bit of book keeping to the system, sure, but it also added a lot of strategy and other situations that just didn't come up. It worked, basically, like this: you rolled initiative as normal when combat started. For every round you weren't hit, or otherwise took damage, in, you added 1D10 to your initiative. When you were injured, your initiative was reduced by your wound penalties (and you didn't get the 1D10 bonus). Finally, if you held action to a later point in the initiative, you permanently changed your initiative to when you acted and had to build speed back up.
This worked great, because it kept theorder for fights more fluid. It was possible, and a valid strategy, to hold action until after an enemy, hit them and lower their initiative to below yours, and then hit them again. A person who jumped into a fight late, got a +20 to their initiative, because they were able to better read and pick their moment for when to enter the fracas. A surprised person got a -20 to their initiative, as their reaction time cost them. Best of all, it made it possible - and easy - for teams to sync up their actions without having to constantly state holding actions. It worked well, and was one of the only games I saw do it. I was sad when it left.
Allowing Unique Player Approaches
There is a small game out there called Mecha that does something really cool with it's combat mechanics. Namely, it lets you assign which one of your stats is going to benefit you in different aspects of combat. This means that the Brainy char, the social char, and the strength char, can all be equally competent in combat without having to sacrifice their core aspects. It also puts intrinsic differences into each character, and keeps a good balance by not letting you use the same stat twice.
Are you the kind of pilot who makes your hits by out maneuvering the other mecha? Then your Agility is probably your attack stat. However, if you get your hits by wearing them down and just doggedly pursuing, it may be toughness. If you banter over the radio and distract them, your charisma. At the same time, you may read the angles of your enemy attacks and move the bare minimum to avoid them (intelligence for defense) or maybe you just take it and tough it out (toughness for defense). It is really cool, and makes for varied characters in an action game more possible. Which is definitely awesome.
Those three aspects together would make for an interesting combat mechanic. You have a flexible but easy base mechanic, a changing turn order to help keep people interested in what is going on, and a system to encourage people to diversify their characters as it won't cost them in a fight.
There are, of course, other aspects that are out there that are great (attacks of opportunity can be cool, as can a lot of the options in D&D, Dark Heresy, and other systems). The fatigue/defense system from the D20 Game of Thrones RPG was also a blast, and something I was sad never made it into other fantasy RPGs. The further depth and balancing act it gave to armor choice was totally worth the additional die roll per round.
What are some of your favorite combat systems? OR aspects of those systems?