A multi-purpose term with multiple definitions that are context-dependant. For example, it could mean “engaging in a silly or humorous act that is not normally committed within societal norms”. Or, it could mean “straight-up fucking”. Originated in a Dungeons & Dragons group, and quickly became common vernacular.
Lunaria invited the maiden to return with her to her quarters to do the wacky.
With behaviour like that, I’d assume you’re doing the wacky!
Used in many improv clubs worldwide to reference an improv topic that takes superior creative thinking and talent to pull off, not a topic like "underwear on your head".
John: Progressive parenting, battle of the wits.
Noah: This is a tough one guys can we do it?
Justin: (pees pants)