Some of you guys may have seen/heard that I'm working on a card-based RPG game. Right now, I'm having difficulties settling on (or just coming up with) a combat system that works with my goal. The idea is that this game is based on the familiar RPG platforms, which frequently use D20s, but is simplified to be playable from level 1 to level 10 in under two hours. To that end, combat should take about 10-15 minutes per encounter, preferably even less. I want to keep the game approachable, as I think that anyone who wants to play a game with lots of record-keeping and mathematics is going to just play D&D, Pathfinder, or some similar p&p RPG.
The current method:
Current method uses a D6. All numbers 1-5 are doubled (2,4...10) with 6 being a Critical. Whether the Critical is a success for failure depends on whether or not the character is using a weapon that they are proficient with. Monsters are always assumed to be proficient with their weapon.
This system is based on a direct transition from the D20's % system. You roll to beat the targets 'Defense' value in order to hit them, and then roll damage according to your attack, which weapon you have equipped, and any modifiers (strength, class ability, magic items, etc).
The Problem: How do I differentiate Weapons under this role, and when everything is hinged on just 6 random outcomes (technically 7 if you count the possibility for critical failure) plus modifiers? Also, do 'Critical Hits' automatically hit, or should they have a better effect? If they auto-hit it could be a bit redundant, since a natural 10+mods will probably also hit. And damage? What should I do for critical damage? Let it count as 12 if you are proficient or a 0 if you are not? Or should it double? Also, only having a D6 at my disposal means that weapons are limited to only having modifiers or additional dice to differentiate their damage profiles.
The Proposed Method:
Someone pointed out the game Super Dungeon Explorer, and my personal love affair with Death Angel, both of which use dice with symbols. For Death Angel they have numbers on all faces from 0-5, and Skulls on half of those. When rolling to hit, you are trying to roll a skull. For SDE, you have Red dice and Blue dice, which have "hit" symbols on them. The Red die is considered "stronger" as it has more 'hit' symbols on it (4 rather than 2, if i recall).
The Problem: this works well, but it changes the 'Defense' mechanic. As Def can be modified by armor and natural abilities, how would I set it up so that you bounce hits? And, further, how do I manage damage under this system?
I have considered issuing players with multiple dice - one for hits, and then an additional 4 dice for damage, split into 2 "greater" and "lesser", numbered accordingly:
Lesser - 1,2,2,3,4,5
Greater - 3,4,5,6,7,8
All weapons would then be combinations of those 4 dice, denoted as a number and letter perhaps. Something like a dagger might only do 1L damage, while a greataxe might be 2G, and the magical hammer Mjolnir might be 2G1L.