Frog Leap
Swap the green frogs on the left with the brown frogs on the right. Frogs only move forward: step onto the empty lily pad, or hop over one frog.
Swap the green and brown frogs. 0 moves / minimum 15
How to play
Tap the frog you want to move. Green frogs go right and brown frogs go left: step onto the empty pad, or hop over one neighbouring frog. Frogs can never go back. Swap the two groups completely to win. Use Back to undo one move at a time.
Learn more
A long-known swapping puzzle. One frog each takes 3 moves, two each takes 8, three each takes 15. For n frogs a side the minimum is n × n + 2n moves: n × n hops and 2n steps (checked by exhaustive search for n = 1 to 5 by this site’s own program). Because frogs can only go forward, one wrong turn can leave a position that can never be finished, and that is what makes the puzzle tick.