This is a tile laying game with a difference.
Normally, tile laying games use either hexagons or squares for their tiles, whereas Keythedral uses octagonal tiles. Ah, but that leaves a little diamond shape in the corners, you say. Exactly, and this game has diamond shape tiles as well to fill those gaps.

The keythedral tile, a diamond shape, is placed on the table. This is then surrounded by octagonal field tiles. Players then lay more octagonal field tiles and also lay one of their cottage tiles, which are diamond shape.
During the game, a players team of workers leaves a cottage and moves into an adjacent unoccupied field to gather resources. These resources are then used to buy the building blocks that build the keythedral. These are kept behind a screen so that the exact number a player has is not known until the end scoring, where a player with the most points wins.

Thats a brief overview. Here is a little more detail:
Phase One - Cottages have a number from 1 to 5. The same numbers appear on the keythedral mat. Workers leave their numbered cottages in an order determined by the players. In this way, you can plan which fields to havest first to get the resources you need.

Phase Two - Resources are collected. These can be black from quarrys, blue from lakes,brown from woods,green from farms or red from vineyards cubes.

phase Three - Spend resources. Each Keythedral building tile shows what resources are needed to buy a seat in the keythedral. The more expensive the seat the more resources are needed, some of which can only be obtained through buying from the blacksmith, glassmaker or goldsmith.
Only one row of seats is revealed at a time, so players can only plan so far ahead. Seats bought are placed behind your screen, out of view.
This phase also lets you upgrade your cottage to a house, which lets you send out two workers instad of one, gaining double resources from a field. Also, fences can be built to prevent opponents from using certain fields.

Phase Four - workers are collected from their fields ready for the next round.

Phase Five - change start player

The game ends when the last tile is removed from the keythedral. Scores are then calculated by counting the number on the seats plus any unused resources.

SUMMARY:
Keythedral plays equally well with two as it does with five. The octagonal tiles and the diamond tiles compliment the gameplay very well and I haven't seen the idea used elsewhere so effectively. Not mentioned above are the Law cards. These cards affect the rules in some way, such as the goldsmith or glassmaker accepting 2 less resources for a gold or glass. We like this game, but then we like tile laying games. Review by Brian