In contrast to a the majority of board games, a tile placement or tile laying game is a game that doesn’t have a fixed, pre-determined play area. The board is created as the game develops, with players placing tiles.
When tiles are placed they can:
1) increase the or change the game play area.
2) provide a scoring opportunity.
Carcassonne is perhaps the most iconic Tile Placement game, but there are many other examples that you will come across.