Jace's Mindsweeper

Target player rolls a D20. (A 20 sided die)
If target player rolls a:
20: He or She wins the game.
19-16: He or She gains 10 life.
15-11: He or She gains 5 life.
10-6: He or She loses 5 life.
5-2: He or She loses 10 life.
1: He or She loses the game.
Return to your hand at end step.