Witch Explained

Witch:

Inventor: @evert823

Notation: W

Movement:

The witch can not capture pieces.

The witch can move like a queen or knight.

The witch can jump 2 squares horizontal, vertical or diagonal.

The marked green squares are squares that the witch can jump to. The arrows indicate where the witch can move.

Ability 1: Being Transparent to allied pieces

The witch is transparent to allied pieces.

Being transparent means that other pieces can move, attack, and capture right through the piece.

Note: Even though pieces can move through transparent pieces, it does not enable pieces to move to the same square as a transparent piece (without making a capture).

Example 1:

Whites rook is allied to whites witch, so whites rook can move through the witch.

Blacks rook is not allied to whites witch, so blacks rook can not move through the witch.

Example 2:

Whites witch is transparent to whites rook and king. Normally castling can't be made when there are pieces between the king and rook, but the witch being transparent makes this an exception. Castling is allowed with transparent pieces between the king and rook (as long as neither the king or rook tries to occupy the same square as the transparent piece).

Example 3:

The diagram above is a team game with red and yellow against blue and purple.

The witch is allied to the red and yellow rook, so red and yellows rook can move through the witch. Blues and purples rook can not move through the witch.

Ability 2: Make adjacent pieces (friend and foe) transparent to allied pieces.

The marked blue squares in the diagram above indicates the squares that are adjacent to the witch. Any piece (friend or foe) on these squares will be transparent to pieces allied with the witch. However, these pieces will not be transparent for the witch.

Example 4:

The pieces on d3, e3 and f4 are adjacent to blacks witch. Those pieces are transparent to blacks pieces. White is in check by both the bishop on c4 and the queen on f6. It is checkmate.

Example 5:

White plays d4. Black captures 2 pieces in one move with en passant exd3 (e.p.)

Example 6:

White plays d4. Black can not capture en passant since it would result in black capturing his own piece.

Summary:

The witch can not capture pieces.

The witch can move like a queen or knight.

The witch can jump 2 squares horizontal, vertical or diagonal.

The witch is transparent to allied pieces.

Being transparent means that other pieces can move, attack, and capture right through the piece.

Any piece (friend or foe) adjacent to the witch will be transparent to pieces allied with the witch. However, these pieces will not be transparent for the witch.

Very nice.

Earlier I had created this pdf:

http://scrybqj.com/scrybqjdocuments/witch_heks_en.pdf

It also describes one case of double capture.

I am surprised with example 3. In team games, with 4 colours, I would have expected that the side-effect of the Witch would be colour-specific, not team-specific. But if the rule described by Martin0 has already been accepted widely then it is of course fine.

I wouldn't say accepted widely, but it is the interpretation that was used in the latest 4-player with witch game:

https://www.chess.com/forum/view/chess960-chess-variants/4-player-bulldog-chess-with-witch-and-archbishop-rychessmaster1-mcgoohan-fly

In games prior to that game, then it was color-specific. Personally, as someone who has played a few team games with witch I considered it a good change and it is what I would use for future games. Some relevant posts:

That is a nice explanation in the pdf. I didn't know that existed. Maybe I'll add a double capture example too later.

Although pieces are not standard transparent to the Witch, two allied Witches will make pieces transparent to eachother. So a Witch can move through an occupied square because another allied Witch made that piece transparent. That should be a logical consequence. Are you also interpreting it this way?

Yes, I also interpret it that way.

Good work on the rules and examples. It's uncommon to make physical variant chess pieces, but here's an example for the witch. Of course other styles are possible.

Double capture with en passant! That's nice and I hadn't thought of that.

Also, nice to see a position of mine in evert's examples. That was a lovely attack that finished with a witch mating move.

I added 2 examples regarding en passant.

I added a summary at the end.

Casting can be done while transparent pieces are between King and Rook. But what if these pieces are enemy pieces made transparent by the allied Witch? And the enemy pieces are on the squares where King or Rook would end. Can we within the same move castle and capture the pieces?

Q1 are the current rules already implying a yes or a no?

Q2 what are the opinions if this must be made explicit with a rule enhancement?

To make this question more clear:

With these two transparent knights, can White castle while taking both the Knights?

(Same question if only one of these Knights was present.)

Result after such capturing castling:

I already have this line written:

"Castling is allowed with transparent pieces between the king and rook (as long as neither the king or rook tries to occupy the same square as the transparent piece)."

So as long as I wrote the rules correctly, it is not allowed to castle and capture at the same time. I don't think the question has previously been raised, however.

From the OP:

"

Note: Even though pieces can move through transparent pieces they can not stop on the same square as a transparent piece.

Example 1:

"

This text should be adjusted. True, the white Rook can't end on the square where the white Witch resides. But the black Rook actually can, and by doing so would capture the white Witch.

In the case of combined castling and capturing, we find enough opportunities to sharpen the texts which describe the Witch. But I checked the FIDE rules:

"...
Castling is prevented temporarily:
...
if there is any piece between the king and the rook with which castling is to be effected.
"

https://www.fide.com/FIDE/handbook/LawsOfChess.pdf

FIDE does not explicitly state that combined castling and capturing is not possible.

My conclusion is: while castling, one can indeed also capture transparent enemy pieces.

I think you take the FIDE rules of chess a bit too much at face value. You read them and try to interpret things that can not happen in traditional chess. I think a better approach is to understand the reason why the rules are as they are and make a decision with the same spirit in mind.

From Wikipedia:

Castling has its roots in the "king's leap". There were two forms of the leap: (1) the king would move once like a knight, and (2) the king would move two squares on his first move. The knight-move might be used early in the game to get the king to safety or later in the game to escape a threat. This second form was played in Europe as early as the 13th century. In North Africa, the king was moved to a safe square by a two-step procedure: (1) the king moved to the second rank, and (2) the rook moved to the king's original square and the king moved to the rook's original square (Davidson 1981:48).

Before the bishop and queen acquired their current moves in the 16th century they were weak pieces and the king was relatively safe in the middle of the board. When the bishop and queen got their current moves they became very powerful and the king was no longer safe on its original square, since it can be attacked from a distance and from both sides. Castling was added to allow the king to get to a safer location and to allow rooks to get into the game earlier (Davidson 1981:16).

The rule of castling has varied by location and time. In medieval England, Spain, and France, the white king was allowed to jump to c1, c2, d3, e3, f3, or g1,[17] if no capture was made, the king was not in check, and did not move over check. (The black king might move similarly.) In Lombardy, the white king might jump an additional square to b1 or h1 or to a2 (and equivalent squares for the black king). Later in Germany and Italy, the king move was combined with a pawn move.

In Rome from the early 17th century until the late 19th century, the rook might be placed on any square up to and including the king's square, and the king might be moved to any square on the other side of the rook. This was called "free castling".

In the Göttingen manuscript (c. 1500) and a game published by Luis Ramírez de Lucena in 1498, castling consisted of two moves: first the rook and then the king.

The current version of castling was established in France in 1620 and England in 1640 (Sunnucks 1970:66).

As I marked in red above, castling was added to allow the king to get to a safer location and to allow rooks to get into the game earlier. Castling has never been allowed to make with a capture. I don't think the FIDE wording really matters. As you know, chess960 has changed the rules of castling quite a bit, they were not restricted to the wordings made by FIDE.

I'm not talking about capturing moves.

What I meant is that a piece can not share the same square as a transparent piece. Even though the piece is transparent, a piece can not move there without making a capture.

Would this wording be better?

Note: Even though pieces can move through transparent pieces, it does not enable pieces to move to the same square as a transparent piece without making a capture.

It's kinda tricky to make the right wording, as sometimes the witch could be played in a variant where you can capture your own pieces (such as the harpy piece). The wording should also not make it sound like it prevents a wild goat to move to a transparent rock.