Crossed fingers

To cross one's fingers is a hand gesture commonly used to wish for luck. Early Christians used the gesture to implore the protection of the Holy Cross. The gesture is referred to by the common expressions "cross your fingers", "keep your fingers crossed", or just "fingers crossed".

The use of the gesture is often considered by children as an excuse for telling a white lie. By extension, a similar belief is that crossing one's fingers invalidates a promise being made.