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Taking place after a huge catastrophe (eg. man made or natural disaster). See also the more political theme dystopian.

Science-fiction. Commonly including things like aliens, advanced technology, and settings of outer space or distant planets. 

Also known as TTRPG, tabletop role-playing games are tabletop games when you play a character within a set of rules. Typically actions are determined by speech and checked for success via dice rolls.