looks cool
New Custom Position for 4PC

Very very cool, maybe the knights should be put somewhere else for non-antichess?
What about this variant?

non-anti need to specify which are the real kings. have you even tried it?
fen for 2nd position? name, rules, suggested time control? ffa,solo,teams?

non-anti need to specify which are the real kings. have you even tried it?
fen for 2nd position? name, rules, suggested time control? ffa,solo,teams?
1) Non-antichess game:
Name: Diamond Wall
Rules:
- Pawns promote on the 11th rank to an any piece.
- Each palyer has 20 lives. (I didn't find another way how to specify the real king).
Variations of game:
- FFA
- Solo
- Teams
(Players can choose any variant of game)
Suggested time control: 1|15D (1 Min + 15s Delay). But players can change time control, if they want it.
FEN4: R-0,0,0,0-1,1,1,1-1,1,1,1-0,0,0,0-0-{'kingSquares': ('k3','c4','d12','l11'),'lives': (20,20,20,20)}-
3,yR,yQ,yK,yP,gP,gK,gQ,gR,3/
3,yB,yN,yP,2,gP,gN,gB,3/
3,yK,yP,4,gP,gK,3/
yR,yB,yK,yP,6,gP,gK,gB,gR/
yQ,yN,yP,3,rP,4,gP,gN,gQ/
yK,yP,3,rP,1,rP,bP,3,gP,gK/
yP,4,gP,rP,bP,1,bP,3,gP/
bP,3,gP,1,gP,yP,bP,4,rP/
bK,bP,3,gP,yP,1,yP,3,rP,rK/
bQ,bN,bP,4,yP,3,rP,rN,rQ/
bR,bB,bK,bP,6,rP,rK,rB,rR/
3,bK,bP,4,rP,rK,3/
3,bB,bN,bP,2,rP,rN,rB,3/
3,bR,bQ,bK,bP,rP,rK,rQ,rR,3
Board view:
2) Antichess game:
Name: Diamond Wall Antichess
Rules:
- Pawns promote on the 11th rank to an any piece.
- Antichess
Variations of game:
- FFA
- Solo
- Teams
(Players can choose any variant of game)
Suggested time control: 1|15D (1 Min + 15s Delay). But players can change time control, if they want it.
FEN4: R-0,0,0,0-1,1,1,1-1,1,1,1-0,0,0,0-0-{'kingSquares': ('k3','c4','d12','l11'),'stalemated': (false,false,false,false)}-
3,yR,yQ,yN,yP,gP,gN,gQ,gR,3/
3,yB,yK,yP,2,gP,gK,gB,3/
3,yK,yP,4,gP,gK,3/
yR,yB,yK,yP,6,gP,gK,gB,gR/
yQ,yK,yP,3,rP,4,gP,gK,gQ/
yN,yP,3,rP,1,rP,bP,3,gP,gN/
yP,4,gP,rP,bP,1,bP,3,gP/
bP,3,gP,1,gP,yP,bP,4,rP/
bN,bP,3,gP,yP,1,yP,3,rP,rN/
bQ,bK,bP,4,yP,3,rP,rK,rQ/
bR,bB,bK,bP,6,rP,rK,rB,rR/
3,bK,bP,4,rP,rK,3/
3,bB,bK,bP,2,rP,rK,rB,3/
3,bR,bQ,bN,bP,rP,rN,rQ,rR,3
Board view:
3) As stated above, I didn't find another way how to specify the real king, so I have a suggestion. Create a new piece in the future. A fake king. It's something like a Quenn with number 1. It's decision help to create a new game where player has multiple kings and should to specify which king is real.

fyi, from https://www.chess.com/clubs/forum/view/4pc-variant-custom-starting-position:
If a player has multiple kings, only one of them is the real, vulnerable king. The other kings will behave like ordinary pieces (worth 3 points in FFA). Think of them as knights that move like kings.
In this case the fen additionally contains the 4 squares of the "real" kings: R-0,0,0,0-1,1,1,1-1,1,1,1-0,0,0,0-0-{'kingSquares': ('h1','a8','g14','n7')}-3,yR,yN,..
As soon as multiple kings are detected in edit position, the kingSquares will be added to the fen (and the real kings will be chosen pretty much randomly). you need to edit the fen by hand if you want to define which are the real kings in a given position.
Spare/Warrior kings are indeed special pieces, with the intentional pun that they serve as doubles for real kings. Unless it's N-check, you won't know which king is a real king until he gets checked. You can also shift-click pieces (shows legal moves) to see the available moves, and real kings cannot move to covered squares.
If you don't want the hidden king effect (players will soon learn and remember which of the 3 kings is the real one), adding 40-check (unlikely to change much) sounds like a good idea.

added diamond wall anti now
https://www.chess.com/4-player-chess?g=1830327
I have tested this game many times. It's working. Little confusion is the feature of the game.
Hello! I would like to add new starting position to the list to play it rated. It's board good for Antichess.
Pawns promote on the 11th rank
R-0,0,0,0-1,1,1,1-1,1,1,1-0,0,0,0-0-{'kingSquares':'k3','d3','c11','l11')}-
3,yR,yQ,yN,yP,gP,gN,gQ,gR,3/3,yB,yK,yP,2,gP,gK,gB,3/3,yK,yP,4,gP,gK,3/yR,yB,yK,yP,6,gP,gK,gB,gR/
yQ,yK,yP,3,rP,4,gP,gK,gQ/yN,yP,3,rP,1,rP,bP,3,gP,gN/yP,4,gP,rP,bP,1,bP,3,gP/bP,3,gP,1,gP,yP,bP,4,rP/
bN,bP,3,gP,yP,1,yP,3,rP,rN/bQ,bK,bP,4,yP,3,rP,rK,rQ/bR,bB,bK,bP,6,rP,rK,rB,rR/3,bK,bP,4,rP,rK,3/
3,bB,bK,bP,2,rP,rK,rB,3/3,bR,bQ,bN,bP,rP,rN,rQ,rR,3