Neat idea. Would have liked a bit of depth in the numbers, as you are always going to want to reroll to a larger number, which ruins the pacing a bit. Would be interesting if 1 had just 1 large jump, 3 had 3 medium jumps, and 6 had 6 little jumps, so your rerolls would affect both the power AND the mobility. Little bit of risk and reward, and adapting to different ways to move. Solid start to something.