‘Core loops’ are a game’s repeated, defining systems of interaction. A player will move through a core loop over and over as they play a game. The leading gameplay action of a game – such as shooting at enemies or managing resources – will almost always be a significant part of the core loop. A fishing game, for example, might see a core loop as follows:

Choose bait > Cast line > Wait for fish to bite > Reel in fish

With a fish successfully caught in that hypothetical game, the player would return to the beginning of that core loop, and once again select their bait.

‘Core loop’ is also a broad term, and can be applied to processes in many types of game. Core loops demonstrate a wild variety of sizes, timeframes and complexity levels. When a game is built up of levels or stages with clear start and end points, playing through those levels could be considered a core loop. A city building title may see a core loop where players invest resources in new buildings, wait for their construction, and then collect resources generated by each property; resources which would be invested in buying new buildings.

Core loops can move players through different areas of your game, rewarding them with in-game currencies and a sense of progress. As such, in some cases they can take on a progression vector role, of a kind. Core loops also provide users with opportunities to spend in-game currencies or real money. They are considerable factors when designing for retention and monetisation.