Single Comment

I'd like to see what H.G.'s take on them would be for the Interactive Diagrams, though, as well as on the Lariat and Shoving Rook.

The Lariat's special move can be written aibuabcaibQ. (Works only with betzaNew.js.) First make a back-and-forth 'rifle non-capture' to select the unload square, and then a normal rifle capture in the same direction to pick off the piece you want to unload.

From your description of the Shoving Rook it is not clear to me wether the piece it displaces should always be pushed to the furthest possible destination, or whether you can choose how far it is pushed back. In the latter case the special move could be cafaibuR. In the other case it would be more complex, as the leg of the move that selects the shoving destination would have to 'sense' that there is an obstacle directly behind it. Such sensing can be done by making an extra back-and-forth King step that must either hop over a piece (p), or go off board (o). E.g. a Rook that only moves maximum distance would be yafpoabR. Using this method in the unload legs would give pafyafpoabyaifuR.

(I rather suspect that the Ghast would need a new Compel spell to do its thing.)

You mean the Ghast from Nemoroth? Indeed. Perhaps even a combination of several more elementary spells. Such as exclude, for making squares in the spell zone inaccessible, and expell for forcing pieces to leave the zone. The latter touches on the subject of forced moves, though (such as mandatory capture in Suicide Chess), which the ID currenly does not implement. Although for check evasion this is implemented in an indirect way.

I guess a similar method could be used for implementing exclusion zones, by adding captures that cover the zone, and declaring every victim that it captures with such moves absolutely royal. This would be an easy addition to the captureMatrix, making it possible to specify some captures as winning game termination. (As the morph can already do, for winning by reaching a certain square.) The 'normal' moves of the piece could then be exempted from this by the apostrophe trick. This way you would not even need a spell.

The problem with the Nemoroth Ghast is that there is no requirement to leave the zone immediately, though. It is already OK to increase your distance. And for friendly pieces it is even OK to keep it the same.

BTW, I don't really see this as coersion, which to me implies a player cannot freely choice his move in his own turn. But it must still be his own action. This is more like "Push and Shove Chess".

And why would you want to swap places with a piece that you could have captured (or push it away)? It seems to me you should only prefer that in the rarest circumstances, so rare that in practice it will never be used. (Like being allowed to capture friends as well as enemies.) So this seems just a rule for the purpose of complicating the rules, which I consider a bad thing in any Chess variant.