I will start the event tomorrow
Event Chess Game (gyrados06 - Bad_Dobby_Fischer)

Event #9 Pit Traps
Both players chooses a square and keep the chosen square hidden to his opponent. The chosen square can not be be occupied by a piece.
Whenever a piece lands on a chosen square, the square must be revealed (regardless who's piece it was that moved there). Then the piece that landed on that square will be removed as though it was captured (it fell into the trap). The trap will still be there after it is revealed, so any piece landing on that square after it is revealed will also be removed.
If a royal piece (normally king) gets removed by walking into the trap, then it is treated the same as if the piece was checkmated (normally a win for the opponent).
Example 1:
White choose the square h4, black choose the square c3. Black plays Qh4. White reveals that h4 was his chosen square and blacks queen gets removed.
White plays Nc3. Black reveals that c3 was his chosen square and whites knight gets removed.
Game continued Be7 b3
Black forgot that the trap was still there and played Bh4 and therefor his bishop was also removed.
Example 2:
White choose the square f6. Black choose the square g1. White plays 0-0. Black reveals that g1 was his chosen square and black wins, since whites king falling into the trap is treated the same as checkmate.
Example 3:
White choose the square f6. Black choose the square g1. Regardless whether the squares has been previously revealed or not Kg1 is a legal move for white, so white plays Kg1 and then looses the game as he walked into the trap.
can you castle through a pit?
that would be like castling through check, and so illegal, but castling through check is not allowed because of the other event
that brings another question
can you casstle through check?

The traps does not affect legal moves at all. As I showed in the second and third examples, it is totally legal for white to move his king to a trap and instantly lose the game (it is not treated as putting your king in check). Naturally, since you are allowed to put your king on a trap you are also allowed to castle through a trap too. The trap will only trigger if a piece lands on that square (could be a rook while castling for example).
Castling works as in normal chess this game, except you also can't castle if it results in checking your opponent. You can't castle through check in regular chess.
Does that answer your questions?
start event (i might get something out of the possibility to capture)