In Nestlings, players assume the role of birds competing to gain priority across four biomes: savannah, alpine, freshwater, and desert.

Each round, players roll their biome dice, then place the dice in biomes one at a time, alternating in clockwise order. Once players have placed all their dice or have chosen to pass for the round, each biome is resolved.

The player who first placed dice in a particular biome gains priority and reaps the rewards of doing so: selecting a resource first, and discarding a resource to thwart their opponents' plans. However, if another player places more of their biome dice in that same biome, that player gains priority. Once priority order has been established for the biome, players each claim resources to feed their nestlings and gain the matching segment to add to their resource ring on their player board.

Once all biomes have been resolved – including the wild grasslands biome in the center of the board – players score points based on how many nestlings they fed and how many segments are in their resource ring, regardless of which round they were assigned.

As the game progresses, the tension rises as players must make key decisions along the way, decisions that could secure victory or usher in defeat. Will they feed their nestlings for more immediate points, or take a different resource to complete a section of their resource ring, thus earning a bonus and triggering a powerful chain reaction? Will they use in-game currency to activate another end-of-game nest goal or save it for victory points? Will they place a second die to secure priority or risk it and head to another biome to take other much-needed scraps?

At the conclusion of round four, the game ends and players reveal their endgame nest goals and tally their points.