St Andrews cross
The St Andrews cross is one of the most common pieces of SM equipment and can be found in virtually every dungeon and club. It is simple to construct, relatively cheap, and very effective in securing someone. Crosses can be made from either metal or wood and can be free-standing or fixed to a wall. All crosses will have attachment points at the extremities for wrist and ankle cuffs; the more sophisticated versions will have adjustable foot rests allowing people of different heights to be bound. Waist, arm and thigh straps are somtimes added to further restrict the bound person's movement.
The St Andrews cross is a very effective piece of kit. Properly bound, the sub will have very little scope for movement. By pulling the arms and legs away from the body the position becomes very open and exposed; they will be unable to protect themselves from whatever the dominant wants to do to them. For this reason, there is a very strong D/s element to any bondage involving a St Andrews cross.
The disadvantage of a St Andrews cross is the tendency of the bound person when tired to hang from their wrists. This makes extended scenes involving a cross problematic. The use of thigh cuffs and crotch ropes can help support the bound person's weight and mitigate this problem to some extent.