Game play

• Each player alternately places a ball from their reserve into any hollow which they have chosen.

Stacking on a square

When one or more 2x2 squares of balls are formed on the board or at higher levels, a player can choose to stack one of their balls on it.

When it is their turn to play, they then has a choice between:

• 1. Taking a ball from their reserve and placing it on the board,
• 2. Placing a ball from their reserve on one of the squares of balls,
• 3. Moving one of their balls already on the board and putting it on a square of balls, but only if this move raises their ball by one or more levels. (This move enables them to save a ball in their reserve. A ball on the board cannot be moved if it is already supporting another balls.)

The third level of balls hides the first level of balls beneath them.

Select a ball on the third level to see a ball that is hidden on the first level.

Square in the player's own colour

A player who makes a 2x2 square of balls in their own colour immediately takes back either one or two of their balls from the board and puts them back in their reserve.

They may recover any ball belonging to them by picking them up from any level of the pyramid - including the one which they have just placed - except for those balls that support other balls.

Note: Making several 2x2 squares of balls in their own colour by putting on one ball only allows the player to withdraw one or two of their balls.

Game End

The winner is the one who places their last ball at the top of the pyramid.

A player immediately loses the game if they have no move. (i.e. can't move up their ball on the board and their reserve of balls is empty.)

BGA variants

Square

These are the rules given above.

Children

To start gradually, it is possible to play without using the rules for the "square in the player's own colour" - only the rules for stacking allow the players to save balls.

Advanced

A player takes back one or two of their balls which are on the board when they make a 2x2 square or a line in their colour.

To be valid, alignments must be on either the first or the second level. An alignment consists of:

• ... 4 balls of the same colour in line on the first level, or
• ... 3 balls of the same colour in line on the second level.

A diagonal line is not an alignment.

No more than two balls can be taken back per shot.