Geeky Glossary
I'm not from anywhere exciting that hasn't already been covered by the midwesterners here, so I'm going to instead focus on terms that come up regularly in my geeky gamer circles:
RPG - "Role Playing Game"/ these come in both video game format as well as "tabletop" (i.e. played on a real table) versions, like the infamous Dungeons & Dragons; but to date there are so many other role playing games out there that this often feels like a serious disservice to the industry (particularly when I don't actually like D&D)
*Bonus: "JRPG" - Japanese Role Playing Game (this is usually a video game, not a table top) or the famous "MMORPG" - Massively Multiplayer Online (think World of Warcraft and similar online games that take a page from D&D-style mechanics)
LARP - Live Action Role Playing / when you do the above but in costume and often outside, rather than indoors
Murder Hobo - role players who would rather see the world burn than follow any type of plot
DM / GM - Dungeon Master or Game Master, the person leading players through a tabletop roleplaying game, aka the conductor of the Murder Hobos
NPC - Non-Player Character, or a character in any game who is not controlled by a player but exists for plot purposes / shopping
"Dudes on a Map" - this is a board game term for games such as Risk which involve deploying troops or figures, usually in a war-style game for control of areas
Eurogame - Europe makes so many complex strategy board games (beyond just Settlers of Catan) that this is now an entire genre of board games
Deck-Building - A style of game where you attempt to build a strategic deck of cards by buying them from a collective pool (example: Dominion)
CCG/TCG - Collectible Card Game or Trading Card Game, such as Pokemon or Magic: The Gathering, where the object is obviously to lose all your money buying cards
PVP - Player versus Player, usually a mode or genre of video game which focuses on players competing against each other
PVE - Player versus Environment, an alternate mode / genre of video game which focuses on players cooperating to beat NPC's or environmental challenges
MOBA - Multiplayer Online Battle Arena, or a game where everyone just kills each other and people sit back and watch on Twitch (examples: League of Legends)
Rail Shooter - a style of video game enshrined by early arcade cabinets like The House of the Dead where all you do is aim and shoot, while the game moves you through hordes of enemies