Branches and Twigs and Thorns

Or, "Barsoomite Go"

An Icehouse set game on a chessboard

Designed by Andrew Plotkin

Branches and Twigs and Thorns is an elegant little strategy game for two or four players. It is a turn-based game, unlike Icehouse or IceTowers; and there is no luck involved. You need a chessboard, a set of Icehouse pieces or Zarcana pieces, and a collection of tokens (at least ten per player).

(The game can also be played with three, five, or six players. You'll need Eeyore's Martian Chessboard sections to make a suitable board.)

Setting Up

Decide who will go first.

Four players:

Lay out the chessboard. The first player places a single token in any square. This represents a null square -- a hole in the board where no-one may play. The second player then places another single token, forming a second null. (He may not place the null so as to completely isolate part of the board. Every square must remain connected. Diagonals don't count.)

The third player places a cluster of four tokens in any remaining square. This represents a root square. The fourth player places another cluster of four, forming a second root. (It is legal for root square to "isolate" part of the board. Roots are not holes.)

Note that 60 squares remain unoccupied. This is exactly the number of pyramids on players' stashes.

Two players:

Fold the chessboard in half (or cover half of it), producing a rectangular board. The first player places a single token, defining a null square, as defined above. The second player places a cluster of four tokens, defining a root square.

Other numbers of players:

For a six-player game, the first three players place nulls, and the next three players place roots.

For a three-player game, the first player places a null, and the other two players place roots.

For a five-player game, the first two players place nulls, and the other three players place roots.


Each player gets a stash of fifteen pyramids, and five tokens to begin with.

Players take turns. On your turn, you place one pyramid in an empty square. The pyramid must be adjacent to a square which is occupied, either by a root or by another pyramid. You must place it lying down, and pointing at the adjacent occupied square. You may not place a piece in, or pointing at, a null square.

If there is more than one adjacent occupied square, you decide which one to point at. Diagonals don't count.


When you put down a piece pointing at the root, that's safe.

When you put down a piece pointing at another of your own pieces, that's also safe.

When you put down a piece pointing at an enemy piece, you take a penalty, and the opponent you pointed at gets a bonus.

You are penalized according to the size of the enemy piece you are pointing at -- one, two, or three points. Put that many tokens into the pot.

The player you pointed at is rewarded according to the size of the piece you pointed at him. He takes one, two, or three tokens from the pot.

(If you need to pay more tokens to the pot than you currently have, every player including yourself should take five more tokens from the pot. This does not change the standing of the game, since only relative scores matter.)

At the end of the game, whoever has the most tokens wins.

A Game

A completed two-player game

This is a completed two-player game of Branches and Twigs and Thorns. The null square (marked with one token) is on the right-side bottom edge; the root (marked with a four-token cluster) is near the top left. As you see, play starts at the root and grows outward. White moved first.

In this game, there are only five moves in which one player pointed at the other. Black made two of these; White made the other three.

To determine the final score, remember that each player started with five tokens. Then add in the penalties and bonuses for each player. The result: White 1, Black 4. Black has won.


Obviously, pointing at the enemy is bad. You want to spread a tree of your own pieces across the board, so that you can always add new pieces to your own tree, and never be forced to grow off your opponents' trees.

If you can surround an open area, so that you're covering more than your fair share of the board, then eventually an opponent will be forced to play inside that area -- growing from one of your pieces.

Every time an opponent plays a small pyramid, he's making himself vulnerable. Do you want to jump on it, choking off his tree and giving yourself more space, for a mere one-point penalty? If you wait, you may have to do it later -- on your opponent's terms -- perhaps losing two or three points.

Of course, you have small pyramids too. You want to play a small pyramid when you attack a vulnerability, so that your opponent gets only a one-point bonus. But then your piece is vulnerable as well. You have five vulnerable pieces, five average pieces, and five strong pieces. Eventually you'll have to play them all. The strategy is deciding when and where.

Aggressive play is not always rewarded, but neither is very defensive play. The last few moves are critical, as the last few open areas are filled in, and players are forced to play their last pyramids.


This game has been through a whole lot of testing and comment, from its original release (Martian Go) to the present. Thanks to Goob, Eeyore, Dan, the Icehouse games discussion list, and particularly Kory (the elegant bastard. He finally managed to kick me into trying the new scoring rule that made BTT what it is today).

Also thanks to Looney Labs for publishing this game in their newsletter Hypothermia 15.

Last updated July 7, 2002.

Martian Go is an earlier version of Branches and Twigs and Thorns. The scoring is simpler, but it has an unfortunate tendency to tie games.

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