duelOnce [ p_ ] :=
Block[{r,survivor,turnNum},
turnNum = 0;
While [True,
turnNum = turnNum + 1;
r = Random[];
If[r < p[[1]],survivor = 1; Break[]];
turnNum = turnNum + 1;
r = Random[];
If[r<p[[2]], survivor = 2; Break[]]
];
survivor
]