DAGGER GOMOKU

Copyright (c) 2003 Bill Taylor, João Pedro Neto

Dagger Gomoku is played on a 19x19 Go Board.

 
  • Definition - The player that owns the dagger can use it to make two placements in the same turn
    • When the dagger is used, its ownership goes to the other player
    • It is illegal to use it to extend three stones in the same line, to make a 5 in-a-row
    • It is illegal to use it in two consecutive turns (except to defend against an immediate loss).
  • RULES - Same as Gomoku, except White starts with the dagger.

The next diagrams show a real match between us (assume [1] is centered, we were playing in a boundless board),


at move [27] Black forces White to play his dagger in gote (bad news)


so White is forced to use the dagger at [28], then Black uses it at [29] to get it back next turn


after White's [32], Black uses the dagger in [35] and [39], making tempos in [37] and [41].
After the dagger at [43] there are now three threats [a] which White cannot defend all.

The moves [37] and [41] are similar to what happens with the Ko rule of Go. A player needs to make threats on other parts of the board, to get back the use of the dagger. This is the only moku game I know that incorporates the idea of Ko fights.

In terms of 'power' available to players, this variant lies between Gomoku and Connect6. The fact that the power to play two stones in not shared, adds tension to the gameplay. A player wants to use it, but he decides to wait for a proper time. It is true that each time he delays, there's a toll on the adversary: the threat is stronger than the execution, as the old Chess grandmasters said. But there is also a danger, as seen in the match above, that the adversary might force you to play the dagger in gote. So, perhaps a player should use the dagger, not to execute an already forced win, but to gain just enough advantage, so to recover the dagger, later, in sente. Also, the existence of Ko fights that emerge from the restriction of consecutive use, is a very good feature. All this is gained from the power imbalance that defines Dagger Gomoku.