Surviving In Another Game Of Death

What was the game?

Mahrez should start with the picking 4 marbles.

Now if Varde picks one Mahrez can pick 5 leaving 1 behind for Varde who in turn has to pick it in the end.

Similarly, if Varde picks 2, Mahrez need to pick 4, again leaving 1 behind.

For Varde's pick of 3,4,5; Mahrez should pick 3,2,1 respectively which will always leave behind 1 marble.

This way, Mahrez can easily survive!