In Animal Crossing: New Horizons, ordinances are rules that you can set for your island to customize your play style. There are four ordinances available: Beautiful Island, Early Bird, Night Owl, and Bell Boom. Each ordinance affects various aspects of the game, such as the behavior of villagers, shop opening times, the economy, and the island's environment. For example, the Beautiful Island ordinance reduces weed growth, increases flower reproduction, and makes villagers water flowers more often. The player can only set one ordinance at a time, and enacting an ordinance requires a fee of 20,000 Bells
. For more detailed information on each ordinance and its effects, you can refer to the in-game resources or online guides and videos that explain the specific features of each ordinance