En Prison

Roulette Term.

A rule applied to even money bets, such as Red/Black or Odds/Evens.

When the ball comes to rest on zero (green), some casinos will allow the player to either take back half his bet or leave the bet (in prison) for another spin. In the second case, if the following spin the outcome is again zero, then the whole bet is lost.

See also La Partage and Surrender.