When something happens that is so improbable, it becomes unreasonable to assume that it’s legitimate. The phrase is a reference to Dream, a Minecraft speedrunner who attempted to write off his cheating as “just good luck”. Dream Luck is often used ironically to undermine the improbability of a given event.

Luck that is unreasonably high. This phrase was created when the popular YouTuber Dream was found to possibly have tampered with in game drops for enderpearls.

Something with a 1 in 7.5 trillion chance of happening, or just something stupidly unlikely and improbable.

Luck that's so bullshit, everyone will call you out on faking/cheating what you were doing, weather you were, or weren't faking/cheating it.

A term used to describe an insanely high number of luck, a number so high that it is virtually improbable

Another term for infinitely good (and definitely not modified *wink wink*) luck involving finding something rare or extremely useful.