Sure... I know there is a couple out there but this is the way I prefer...(taken from another rp thread Xan's in...though no fights have started yet)
Both parties start with 50Hp.
Whoever is first rolls 1 - 10 sided die
Whoever is second rolls 2 - 10 sided die
First person rolls again, 2 - 10 sided die...etc.
The first roll is defense, the second is an attack (The first person only needs to roll once, since they aren't defending yet.)
First to 0 has to surrender (since soq can’t die)
Example
Xanti attacks - (rolls dice, lands a 4)
Blake retaliates - (rolls two dice, one is a 5 and one is a 8 )
so Xanti's attack is canceled out by Blake's 5
Xanti retailiates - (rolls two dice, one is a 3 and one is a 6 )
so Xanti's is down by 5 hp
Blake retaliates - (rolls two dice, one is a 3 and one is a 5 )
so Xanti's is down by 5 hp and Blake is down 3
and it continues on like that.