Chess variant idea(s)
Each player has one spy among their opponent’s pieces.
On your own turn, you can switch out one of your opponent’s pieces for an equivalent piece in your color (e.g., black rook for white rook), then move it as one of your own. Ever after, it is one of your pieces.
Possible variants:
- Reveal your spy on your opponent’s turn instead of your own (you take their turn instead of them taking it).
- Reveal your spy on any turn.
- More than two spies.
- Unlimited spies.
- Double agents (after revealing your spy, your opponent can reveal that it was their own spy, taking the piece back, ending your control of it).
- Arbitrary-multiplier agents (revealing a double agent does not end control: a N-ple agent can always be revealed to be an N+1-ple agent).
- A requirement that you choose your spy beforehand and seal the knowledge in an envelope (rather than choosing the spy to “reveal” at any time). Open the envelope when you reveal your spy.
I don’t know enough about chess to be able to predict how well this would work, or whether anyone has thought of this before (it’s quite likely).