Comments/Ratings for a Single Item

If the Pentere/Quinqereme is notated by P, then how are the pawns notated
by?

Knappen is one of the best variant designers, and his work is a huge
inspiration to me. Kudos for an ingenious game with an intriguing type of
nightrider that moves as a camel every other move.

Here is a curiousity I discovered in a game I just started: 

If White moves the f pawn on the first move, black's unprotected pawn at
j10 is threatened by the Pentere, also threatening a nasty double check,
which would force the king to flee. j10 is an unprotected pawn. 

The problem with unprotected pawns in opening positions is not that they
make a more inferior game than otherwise for the second player. That's a
common misconception. It is simply that variations can be forced, giving
the game an immediate tactical edge sometimes not allowing for the
flexibility many prefer to have in their opening choices. For a large
variant, I don't that's a bad thing. 

Please note: The forced moves will only happen if one of the players
decides it would be of advantage to force them, just as it is optional
whether to create the sort of pawn structure which leads to an open or
closed game.

'My question is rather specific, in the duodecimal variant I am just designing there are standard knights and bishops, and I want the endgame of king & knight & bishop vs lone king to be a win.' - Jörg Knappen, regarding the 50 moves rule.

Sorry to be so late! Your 12x12 board requires at least a 100 moves rule, as the length of a forced checkmate (or other victory) seems to increase in proportion to the number of squares on the board. Here are some known facts on the 8x8 board. K+B+B can take 19 moves to mate. K+B+N can take 33 moves to mate. K+Q versus K+B+B can take as long as 71 moves to force the first capture. K+R+R versus K+Q only takes 15 moves (30 ply) to force the capture of the Queen, but it takes much longer if the defender has a [C]hancellor (Rook + Knight) or a [U]nicorn (Bishop + Nightrider).

	* Fairy endgames with 3 pieces' * Dave McCooey *
     ------------------------------------------------------------------
     |||||        Longest Wins for the Strong Side (WHITE)        |||||
     ------------------------------------------------------------------
Three            Number   Type                                      Side
Piece      Half    Of      Of                                        To
Endgame    MovesPositions Win       Example Position                Move
-------    ----- ------- ------- ---------------------------------- -----

KRRvKQ       30       14 f-captr WK(c8) WR(h2) WR(g8) BK(a1) BQ(d1) WHITE
KRRvKU      202        4 capture WK(b8) WR(d5) WR(h8) BK(d7) BU(e1) BLACK
KRRvKC       87        9 capture WK(d6) WR(a6) WR(a7) BK(g6) BC(d3) WHITE

KQvKBB(xdd) 142       74 capture WK(b8) WQ(a8) BK(e5) BB(e6) BB(f8) BLACK

I think you should make the part where there is Leeloo, space Pentere, Leeloo become space, Leeloo, Pentere, space. The Leeloo is clearly stronger than a Chancellor (Rook + Knight), and a Chancellor (Rook + Knight) is about as strong as a Queen. Therefore, the Leeloo is stronger than a Queen, so there should just be 1.

For what it's worth, I've looked at the logs of finished games of this variant (just 2), as well as such logs of Alekhine Chess and my own Sac Chess, as these are two large board variants I've known that have lots in the way of powerful pieces in the setup provided by the inventor.

It may be arguable, but I consider the number of moves played in an average game of a given variant to ideally be about 40 moves (what it is for the ever-popular standard [FIDE] chess) before most players would seriously consider ending the game (i.e. not play it out to checkmate or a draw by regulation rather than agreement, in the case of chess at least).

In the case of Alekhine Chess there's 8 finished games so far, and only two have gone past move 30; I suspect that the board having only 8 ranks (in spite of 14 columns) leads to more speedy finishes as a rule, given that there are also many powerful pieces in the setup. There's about twice as many games of Sac Chess finished thus far, with most lasting 30-70 moves before resignation or checkmate. Sac Chess is 10x10, with less squares in total, but even more in the way of powerful pieces in its setup (e.g. 2 Amazons per side, rather than 1) than in Alekhine Chess. Not enough finished games of either variant to be totally convincing, but note at least some of the games had fairly evenly matched and/or relatively high rated Game Courier opponents.

It's even less convincing evidence in the case of Quinquereme Chess (12x12 variant, with plenty of room for powerful pieces in the setup, it seems, when recalling the previous paragraph), with just two finished games of it so far, but note each of these at least had a nice number of moves played, in total, compared to the average length of a game in chess. I suspect based on all the above that at least one very powerful piece could be added, rather than subtracted from, this variant and still not seriously hurt its as yet far from proven playability, or the possible nice length of an average game of it.

There is one small imperfection in the diagram's implemenation of Quinquereme Chess: It allows the King jumps to the back rank also when in check. Perhaps I should make it a general property of the diagram that initial moves on a royal piece are not allowed when in check.

Thanks for featuring Quinquereme Chess with an interactive diagram! Unfortunately, there is a glitch in the implementation of the Quintessence and its compounds, it is lacking the lateral development like

f5 - d6 - c4 - a5

or

f5 - g7 - e8 - f10

I guess, the initial "hq" is too much and suppresses some moves. The Quintessence in Nachmahr without the initial two letters "hq" works fine.

Ah yes, you are right, I mixed it up. It were all the other Nightriders that needed to distinguish left and right turns; the Quintessence has both. In Nachtmahr I got that right. I fixed it now.

BTW, these 'wide' pieces with their very long, folded trajectories gave me crazy idea: what if there was a piece with a trajectory that would cover the entire board? E.g. sliding along a path that wrapped around it like a spiral:

24  9 10 11 12
23  8  1  2 13
22  7  X  3 14
21  6  5  4 15
20 19 18 17 16

To keep it somewhat symmetric it could also wrap anti-clockwise.