[Warning! TVTropes!] A Dump Stat is a gaming concept: a quality in the game that you choose not to allocate any character-building resources to (and thus your character does not possess). Say, your character is a wizard, and has really low strength because you traded it for intelligence (which usually translates to spell-casting power).

Wizard, design by Hojyo Takashi, photo by Origamiancy, CC BY.
This guy’s dump stat is definitely fire resistance.
I think my dump stat is probably all-nighters. Can barely stay awake at all: certainly the amount of work produced is nowhere near worth the cost, which is basically a full-on hangover the next day regardless of use, or lack thereof, of intoxicants. And I don’t find them fun. So, I would definitely have no points in all-nighters.
How about you?
Quick note: let’s try and keep this light ok? Stuff you’re OK with being bad at, rather than stuff that tears you apart. And steer clear of “and I don’t care because [whatever skill] is universally useless anyway!”: you can be sure someone here will be into it.
This is also an open thread for any other topics of interest to you. Comment policy applies.