Nerdy lines are a compatibility test disguised as a joke — the whole point is that only the right person laughs. Aim the reference precisely: a physics pun on a physicist, a D&D line on someone who knows their armour class. A missed reference doesn't offend, it just dies quietly.
The braver move is using one in a decidedly non-nerdy venue and seeing who catches it. Whoever laughs is your people.
Nerdy lines do something most openers cannot: they screen for compatibility while they charm. The person who catches your obscure reference has just told you something real about themselves, which is more than any generic compliment achieves. Conventions, game shops, campus and the deeper corners of the apps are the high-yield venues — anywhere the references are load-bearing.
Specialist ammunition lives in the sub-collections: computer science, math, physics, Star Wars and Star Trek. Aim precisely.
