Knocking on wood

There are connections between ancient spirituality and trees influencing fortune.

In the pre-Christian beliefs of the Germanic people, for example, three Norns send fate up into the universe through a tree.

Meanwhile, the ancient Celtic peoples also believed that the act of touching wood called on spirits or gods of the trees.

[1][2] Christians tie the practice to the symbolism of the wood of the cross of crucifixion.

[2] Folklore researcher Steve Roud suggests that the widespread, modern use however derives from a form of tag called "Tiggy Touchwood" in which players are safe from being tagged if they are touching wood.