It's weird, if you turn "legal moves" off, then you can move any piece anywhere on the board, and you can move without you opponent moving (only on the analysis screen though - it doesn't happen in the real game)!
"Legal Moves" Option

The story so far ...
- The Analysis Board used to enforce Legal Moves.
- Some people complained it gave an unfair advantage
- It was disabled.
- Some other people protested that the change was ridiculous.
- It was reinstated as an option, defaulted to being switched on.

The story so far ...
The Analysis Board used to enforce Legal Moves. Some people complained it gave an unfair advantage It was disabled. Some other people protested that the change was ridiculous. It was reinstated as an option, defaulted to being switched on.Thanks, but "unfair advantage". Hmmmm. And what would an illegal move be, something like castling when you're in check, I suppose?

I like the “legal move” feature of the analysis broad; you can turn it off to model the long term positional goals of an opening or to imagine strategic possibilities beyond the scope of the early midgame (i.e. the Board as it is legally). Anyone who would use the legal move setting on the analysis broad to “cheat” could use the regular correspondence in the same because the only moves that can played … are legal.
The analysis screen has a box to check which limits one's options in the hypothetical game to "legal moves". Huh?