Core gameplay loop
A core gameplay loop is the short cycle of actions a player repeats, with a reward that gives a reason to do it again.
Also called core loop, game loop design, gameplay loop.
The core loop is what a player does over and over and the reason they want to do it once more. Most games have loops inside loops, from a few seconds of action up to a long arc that ties many sessions together. When the loop works, players keep going "one more day" at midnight; when it doesn't, every system you add feels like a chore.
What makes a loop work?
Each step should create the need for the next one. A step that doesn't feed anything becomes optional, and optional steps get skipped. Rewards also need somewhere to go: if materials pile up with nothing to spend them on, gathering stops mattering.
The loop in Mytheria
The day loop takes 12 real minutes: gather and explore by day, decide whether to risk a night where creatures grow ten times stronger, and wake up together at dawn. Around it, the region loop has five steps: enter a region underpowered, gather its materials, restore its settlement, forge better gear at its workshop and beat its boss, which opens the next region. Each region is about three times harder than the last, and gear scales to match.
The full post, with clips and demos Game loop design: gather by day, survive the night