MSO - TwixT, an introduction

TwixT - an introduction

By David J. Bush

TwixT is a two-player abstract board game, invented by Alex Randolph. It's one of the first "connection type" games, a genre which includes Hex and Havannah. "Connection" means the object is to form a path which connects something to something else. This kind of game requires a very different sort of visualization from the standard "battle type" game such as chess.

Unfortunately, new TwixT sets are not currently available in the USA. In Germany, the Kosmos game company has a new edition of the game. Used sets are on auction at Ebay.

Rules

The board is a 24x24 square grid of holes, minus the corner holes. The holes along the edges are referred to as ‘border rows.’ The ‘top’ and ‘bottom’ rows are White's border rows. The ‘left’ and ‘right’ edges are Black's border rows. (Sets may use different colors from Black and White.) Each player has a collection of pegs and links of his/her color. The board is empty at the start of the game:

White moves first. Each move consists of one or two steps:
1. Place one peg of your color in any vacant hole, EXCEPT for your opponent's border rows.
2. Place as many legal links as you wish between pairs of pegs of your color. A link may be played only when both pegs are at opposite corners of a six holed rectangle, like a knight's move in chess, and no other link crosses the linking path, not even one of your own. You ARE allowed to remove as many of your OWN links as you wish, prior to placing any.

Usually, players choose to place all possible links that can be added to the peg just played. Links are rarely removed, but sometimes you need the elbow room.

After White makes the first move, the opponent has the option of either responding normally as Black, or swapping sides. If sides are swapped, the player who moved first as White is now Black, and makes the next move.

The object is to connect your border rows with an uninterrupted chain of linked pegs. If neither side can complete such a chain, the game is a draw.

Draws can occur when one player has an impenetrable barrier to the other, but this barrier is not an uninterrupted chain. Here is an example:

White's barrier prevents Black from connecting left to right, and Black's pegs and links prevent White from forming an unbroken chain.

Here is an example of a position where link removal is necessary:

White can win from this position by playing at N3, removing the links L3/N4/P3/Q5, and then adding the links L4/N3/P4/R5:

Move Notation

There is a more concise way of describing the above move: N3-L3/N4/P3/Q5+L4/N3/P4/R5
The minus sign - is followed by a chain or chains of links to remove. Chains are separated by commas. Then the plus sign + is followed by any chain or chains of links that are added. The above move could have also been indicated by: N3-L3/N4,Q5/P3/N4+L4/N3,N3/P4/R5
Fortunately, the vast majority of moves do not involve link removal. They are indicated simply by the coordinates of the hole where the peg is placed. Any links which can be added to this peg, without removing other links, are automatically added. Some players like to include a symbol (usually an asterisk * or a dash - ) after the coordinates, one for each "auto link" played.
If you choose not to link to the peg just played, even though you could, this can be indicated by the + symbol with nothing after it.

More TwixT: Basic Strategy; Handicapping

I emphatically welcome all questions, both general and specific, as well as any comments you may care to send me! My email is: twixt@cstone.net