Celtae is a "worker swapping" game powered by a rondel in which players choose actions to perform during their turn. On their turn, players swap one of their three active workers with one of the three workers on the action space they wish to perform, then they perform the action — which will be boosted if they have in their worker pool specific types of workers: farmers, builders, soldiers, and nobles. Each time the action marker on the rondel completes a full turn, the player who currently holds the favor of Teutates places a progress marker on one of the progress cards next to the game board. At game's end, only progress cards with progress markers will score, so as the game advances, players determine what will score...and what will not.