Topic on Talk:Gambling Game
This is a permanent link to the first version of this post.
You can view later versions on the post history page.
I can see a distinction there. Blackjack can be played without wagering anything; at its root, it's a contest of who knows probability math well enough to come closest to a score of 21 without going over. Poker, on the other hand, has an element of psychology (the bluff or lack thereof) in addition to the probability math needed to get a decent hand, and it's that psychology that leads to the gambling - even if all that's being risked is one's reputation as a good player.
Nothing in the trope description as it read when I posted this requires the gambling stakes to be tangible.