Touch wood / Knock on wood Informal

Said, often while literally touching or knocking on something wooden, to ward off bad luck after making a hopeful or confident statement.

It reflects a superstition that voicing good fortune aloud might tempt fate, and that the small ritual of touching wood offers a kind of protective counter-measure.

The superstition’s origin is genuinely disputed rather than settled. One theory ties it to ancient Germanic and Celtic beliefs that spirits or gods resided in trees — Germanic legend held that the three Norns (fate goddesses) sent destiny into the world through a tree, while Celtic tradition held that touching a tree could invoke its protective spirit. A separate, later theory connects the gesture to Christian veneration of the wood of the cross of the crucifixion, reinterpreting an older pagan practice within a new religious framework. A third, more modern and more skeptical theory, proposed by folklorist Steve Roud, traces the widespread current form of the custom to a 19th-century children’s tag game called “Tiggy Touchwood,” in which players were safe from being tagged as long as they were touching a wooden object — a playful rule that may have helped popularize (though probably not originate) the superstition in its current form. No single explanation is conclusively proven; the practice most likely draws on several converging traditions rather than one single, traceable source.

We haven’t had any problems so far — touch wood.

I’ve never broken a bone, knock on wood.

The car’s been running fine, touch wood.

A: Are you feeling better? B: Much better, knock on wood.