In Counter-Strike you get in-game money for doing things right during the game that you can spend on items that make you better compared to your opponents, but if you die you don't get those items back. In the abstract this is a skill-based type of gambling, but ultimately the fix you can only get from gambling is tempered in Counter-Strike by the fact that your winnings and losses have no persistence (When you log in to a server you always receive what, $800 to $1,000?) and that there are mechanics that keep you from losing your shirt (namely, you can only die once a round).
DUST 514 took this core emotional experience and added to it a persistent money total that existed outside the game as well as items that actually cost irl money (which provided marginal but not immaterial advantages over the items that cost f2p money). Additionally it used the Battlefield method of scoring deaths instead of the Counter-Strike method so you could (and from my interactions with more degenerate / less financially savvy DUST bunnies, often would) basically play yourself into being a broke-ass Treasure of the Sierra Madre character. Over time they even added more gambling mechanics like the Dota 2 chests that contained items with varying degrees of worth or efficacy instead of hugbox skins of varying degrees of embarrassment. Any regular of the game
was a Caldari whether they believed it or not. The premier (only?) podcast for the community regularly discussed things in economic terms, and not the broad, analytical sense you find in articles about EVE written by those who exist without the community, but in the cold, brutal logic of a homo economicus. (No homo.) I know there were other reasons for this, but I don't think it was a coincidence that the game had a strong presence in markets more subject to the callousness of international capital than Western Europe or anglophone North America like Brazil.