Start up a game in any mode. I did this in CTF while working on the other achievements. Put an opponent up against a wall, facing you. Stand against the wall a decent distance away, facing them. Throw a Kunai at yourself with the opponent by tapping
. Pretty quickly after doing that you need to tap
on your controller to slash and deflect it, then deflect it back with them using
, and deflect it back once again yourself using
. This counts as the 3rd deflection (one deflection by you, the 2nd by opponent, and the 3rd by you) and will unlock A Dangerous Game.
You can see this achievement setup in action starting at
9:25 in the video below.