Blokus

A JS driven implementation of Blokus, with a Rails API version.

There are 21 pieces per player.

Rules

1. First block placed must cover a corner square.
2. Subsequent blocks of the same colour must touch a corner of a block of the same colour, but cannot share an edge with a block of the same colour.
3. A player is out once they can no longer place a block on the board.
4. Game ends when no players can play a block, either because they are blocked or have used all their pieces.

May add rules for three and two player games later.

Scoring

Basic Scoring

Player with the lowest number of unplayed squares wins.

Advanced Scoring

Each player counts the number of squares in their remaining pieces. 1 square = -1 point. A player earns +15 points if all of their pieces have been placed on the board plus 5 additional points if the last piece they placed on the board was the smallest piece (one square).

Alternative Scoring

One point for each board square covered, +15 if all pieces used. +5 if last piece player placed was the 1 square piece. (Max = 109?)

Block Positioning Validation

Create a BlockDefinition for each of the 21 blocks.

Validation Checks for blocks need to look at:

• If it is the first block a player has placed, it must cover a corner square of the board.
• That the positions are not used. Can check this by finding all the positions that have been used on the board by blocks.
• That at least one corner is touching the corner of another block owned by the placing player
• The block being placed does not share edges with any block owned by the placing player.
• That the given positions match the shape defined in the BlockDefinition for the particular block type. Horizontal / vertical line checking is easy, doing complex shapes is harder. 8 possible forms for each block. Could create a shape centered on 0,0, then apply each transform to find a match. Some shapes have less than 8 forms, for example the cross only has one form.

TODO

• Move shapes to the DB
• Support for 2-4 players
• Test board.js

Extras

• Extended hint mode: show which pieces can be played where
• An AI to play against
• Support different game types, eg duo & trigon

Notes

• Blokus Variations
• Barasona opening
• Pentobi
• Pentolla