Kingdom Builder is a strategy world-building game where you create a kingdom by placing settlers' houses. You work to build settlements with positions and orientations that meet three specific criteria chosen at the start. This, along with special Location abilities that let you move and grow your settlement in different ways, create a game that is both simple to learn but has considerable depth.

The board is constructed when you start and varies each play. Before starting you pick three Kingdom Builder cards that define the gold scoring rules for the round. This might require you to build near mountains, form horizontal lines of buildings or build next to castles' terrain.

Each turn you place three settlement tokens on unoccupied hexagons matching the terrain type you draw (grass, fields, deserts, forest). You have to place them adjacent to any existing settlements. If you build next to the Location tiles you get special actions each turn like placing additional settlements or moving an existing settlement. When someone has placed all their settlements when someone places the last settlement.

What starts as a simple placement game quickly evolves into a competition for space. Placement is restrained to start with and so less combative, but as you get more Location tile special abilities you can move into areas other players are working on and even bridge your settlement across rivers. All the while players are competing to find new ways to meet more Kingdom Builder criteria and score more points.