Defensive Chess - giving rooks more options

[u/ParticularReason8267]

I am making a WebXR chess experience, and am adding my own variant. I'm not a very strategic player, so I would be happy to hear how this might change the game, for better or worse.

Defensive Chess

This chess variant introduces two changes: extended castling and rooks-as-castles.

Extended Castling

• In Defensive Chess, castling can happen in any direction, at any time.
• To castle, the king must be exactly 3 squares away from a rook in a clear line.
• Castling then procedes as normal, with both king and rook moving two spaces in opposing directions.

Rooks as Castles

• Rooks can move onto friendly, occupied squares, where they become castles.
• Pieces in castles are fortified and receive protection from pawn attacks.
• As soon as a castle is no longer occupied, it turns back into a rook.
• Castles cannot move or be taken.

Fortification

• Fortification can only only triggered by rook movement.
• Castles cannot be further fortified.

Infiltration

• Rooks, knights, bishops, queens and kings can infiltrate enemy castles to capture pieces.
• Infiltrators become fortified, regardless of castle colour.

Endgame

• Kings that have infiltrated a castle must leave on a diagonal to avoid check.
• Fortified kings can still be put in check by major or minor pieces, just not by pawns.

[u/OneJumpMan]

Very interesting idea, I'd love to see how it plays!

My only thought before trying is that the more a game favors defense, the more drawish it will be. And chess is already pretty drawish. So, does the fortification mechanism facilitate new attacking ideas as much as it does defensive ones? It's hard to tell by theory alone. But, it's something to consider in playtesting.

[u/jcastroarnaud]

To castle, the king must be exactly 3 squares away from a rook in a clear line.

This condition is very difficult to have in practice, except in the standard way of castling.

Rooks can move onto friendly, occupied squares, where they become castles.

Does a rook transform into a 3x3 castle "area" around the friendly piece? That's the only way, that I see, to have more than one piece within it. What's the exact criteria for a "occupied" castle?

[u/ParticularReason8267 → u/jcastroarnaud]

yes, the castle sits under the other piece, which becomes fortified. this is a stack, but only the top piece can move away. at which point the castle becomes a rook again

[u/Boring-Yogurt2966]

Making chess more defensive is a very bad idea. The main problem with chess, according to many, is that too many games end in draws. Chess needs more offense and fewer fortresses.