To stay up all night and play Super Smash Bros with AI or friends. These STD meetups are sometimes used as training for competitions where a player is expected to perform for lengthy periods of time.
Bill: Hey, you have any STDs coming up?
Andy: Yea next week;
Bill: Its not gonna be just you and me, is it?
Andy: Nah, I got 2 other peeps that will Smash Till Dawn with us.