Jens Baek Nielsen invented this game, and wrote about it in Issue 67/68 (December 1994) of ETEROSCACCO, the periodical of AISE. The rules were shaped in games with, and improved by suggestions of Torben Osted and Ian G. Richardson.
The usual rules of chess apply, with the following modifications:
More details on this variant can be found in Issue 67/68 of Eteroscacco. Here is the shortest of the sample games given there. White is Jens Baek Nielsen, black is Ian G. Richardson.
|3.||B g2?,||B x f2 + !|
|4.||K x f2,||Q h4 + !!|
|5.||N f3 x h4 (doublemove),||N f6 +|
|6.||K f1,||N x g4 + (after 6. Kf3, N c6 d4 (doublemove) follows)|
|7.||K g1,||N c6 d4 (doublemove)|
The inventor wrote about his game:
... this chess variant has a lot of active and interesting play - the twiknight influences the game all the way through.
It has good speed, and in my point of view it has an advantage to progressive variants, where series of 6-7 moves or more are so hard to calculate that it is a little random who wins the game.
Indeed, the sample games show that the knights have a formidable attack on the enemy king.