Warcraft has one. Runescape has one. Elder Scrolls. The Witcher. Even Plants vs. Zombies.
Now, Titanfall has a card battling game too.
An official site for Titanfall Frontline has popped up online (thanks, Wario64). The app has yet to launch, although the site includes screenshots and information.
Frontline is described as a "fast-paced head-to-head strategy card battler" for iOS and Android devices.
As you'd expect, there are character cards, Titans and match-modifying burn cards.
Cards have an energy cost to play and what looks like attack and health stats. In all, there are hundreds to collect.
There will be "real time competitive PVP", leaderboards and social guilds, as well as the opportunity to upgrade and customise cards.
We'll keep an eye out for more information and let you know how much the game costs to play.
Frontline will no doubt launch around the same time as the next proper Titanfall game, Titanfall 2, which arrives for PC, PlayStation 4 and Xbox One on 28th October.