### Sudoku as a City Building Game

Since playing Qwirkle, Iota, and lots of trick-taking games, I've been interested with the idea of denial-by-set. In other words, "you can only play X, Y, or Z onto this space based on what has already been played." In most games, the rule is that you can't play duplicates. For example in Guildhall, you build columns of cards with identical titles, but they must all be different colors.

Sudoku uses this rule as a way to make puzzles for you to solve. So I thought about Sudoku puzzles as a mechanism for city-building. Here's the quick outline:

Overview...
• Assume this is a game about building Rome for now. I'll think of something better later.
• There is a 9x9 grid, but that may change later. I'm only assuming that now because of the Sudoku inspiration and I prefer to change one thing at a time.
• There is a general supply of tiles. All tiles are colored corresponding to a particular player, though they are not "owned" by that player. Any tile from the supply is accessible to anyone.
• Tiles feature buildings like like Bazaar, Temple, Park, Arena, and so on. These buildings also allow you to take an action at the moment you build it. For example, the Bazaar lets you buy stuff.
• Environmental tiles are placed outside the grid that grant conditional effects to certain rows or columns.
• Take a tile from the supply, then play any tile in your hand.
• To build a building, you just take a tile from the general supply and place it onto the grid. You sometimes must spend tiles from your hand as construction material.
• The most important rule is that you cannot put it in a row or column which already has that building present.
• The length of the row or column on which you place your tile grants bonuses to the action you take on that turn. For example, placing a Bazaar on a long line lets you buy more stuff than if you place it on a short line.
Endgame...
• The endgame is triggered when there is no longer a legal play to be made.
• Players score bonus points for having the majority of tiles of their color on a row or column.
• Environmental bonuses may also grant extra points.

That's the loose outline anyway. I imagine you could further complicate matters by granting synergistic effects to surrounding tiles or tiles in the same row/column. It can get kind of nutty.