Luck

Luck was believed to be, according to the Eleventh Doctor, "an intangible force that helps [gamblers] win or lose". He deduced that Joe Buchanan had faith in luck from his dice cufflinks and horseshoe chain. The Minotaur fed on Joe's faith in luck, killing him. (TV: The God Complex)

"Jinxing" is when someone says something similar to "waht could possibly go wrong". The Doctor is known to jinx himself with such statements, and immediately regrets it. (TV: Midnight, The Doctor, the Widow and the Wardrobe, Time Heist, In the Forest of the Night)