I'm developing an RPG (goodness, I'm doing a lot actually.) and I'm trying to come up with a decent die roll mechanic for skills.
In d20 systems, it's usually
Die Roll + Skill + Bonuses - Penalties >= Some Target Number
For Many Warhammer (old) systems, you:
compare skill vs. skill on chart, Die Roll >= # given on chart.
For the HERO system, it's generally:
Roll 3D6 <= Skill + Bonuses - Penalties
But for each of these systems, they use a different die mechanic to determine the outcome of the action. D20 is notorious for using D8s, D10s, D12s, etc. Which you total up, and deal to someone else. That other person is then fine until they drop to 0hp. (other games are similarly designed, HERO for example using Body, STUN, and END).
Are there games that discard a second mechanic for action resolution as well as success?
For example, I'm thinking of using a black-jack mechanic.
Die Roll <= Skill + Attributes + Bonuses - Penalties
to determine if an attacker hits an opponent, and then that opponent must "resist" the damage caused by the attack, using a very similar roll. This is used on the table-top Warhammer games (Roll to-hit, Break Toughness, Armor Saves).
Damage is measured in penalties instead of in numbers. (ex. if a combatant failed 2 resists in combat, he'd suffer a -2 penalty for all other skill rolls). The penalties being easy to see/keep track of using counters etc.
- What pitfalls am I missing?
- What games use a mechanic similar to this?
- What other mechanics should I be concerned about?
[EDIT] Thanks for all the answers. These are really great.
Damage and Death
So the game has two types of damage, Injury and Wounds.
Each Injury (IJY) over the Injury Threshold (IJT) gives the player a -1 penalty. If the number of IJY exceed the Injury Limit (IJL), they are converted wounds instead.
Each Wound (WND) over the Wound Threshold (WDT) gives the player a -4 penalty. If the number of wounds exceed the Wound Limit (WDL), they go into a coma and begin to die.
So for the complete n00b, the numbers would look something like this:
- Injury Threshold 3
- Injury Limit 6
- Wound Threshold 0
- Wound Limit 3
A mid-level cyborg might look something like this:
- Injury Threshold 6
- Injury Limit 12
- Wound threshold 2
- Wound Limit 6
Able to take far more damage, and shrug off the first few strikes in combat.
Healing will also be non-random, and if a character uses a healing item - there's no roll or chance involved. They gain the benefit, and can go on with their life.
I like very much the mechanics in Feng Shui and in DnD 4E in regards to Minions, Monsters, and Villains. I intend for Minions to have Wound Limits of 0. (one-hit kills) while Villains would be large, hard-to-take-down mosters where tactics and cover will be your best friends.
Similar to HEX, players can spend "points" the earn during roleplaying to negate bad rolls, or improve good successes. Players are not just at the whim of their dice, but can use other resources like points tactically.
And yes, this is intended as a table-top turn-based game.