Risky is a new option introduced in DanceDanceRevolution X2. It is an option that sets the player to a single-life battery meter, similar to the ENCORE EXTRA STAGE. When a player makes even one mistake, they fail the song but are allowed to continue up to Final Stage (if on Final Stage or EXTRA STAGE, the credit ends). If the player fails any song with Risky on, then they will not be able to access the EXTRA STAGE. It is useful for trying to get a Full Combo on a hard chart. Risky is represented by a skull.
Risky is not available on Versus play because it would be unfair for one player to get a Game Over (in other words, fail the song) and the other player to clear the song, then the player who failed could continue up to the next stage or Final Stage.