Final answer:
Roscoe was caught playing poker at Gina and Pam's apartment. Poker is a card game that combines gambling, strategy, and skill.
Step-by-step explanation:
The gambling activity that Roscoe was caught participating in at Gina and Pam's apartment with friends was playing poker. Poker is a popular card game that involves betting and individual play, where the winner is determined by the ranks and combinations of their cards, some of which remain hidden until the end of the game. It's commonly played in various settings, from casual home games to professional casino environments.