A ladder that lands on a snake's head can loop forever

transcript

This snake and ladder board can loop forever. Not the dice. Not the players. Just one ladder.

You land on 4. A ladder takes you up to 14. But a snake's head is waiting on 14. Do you slide to 7? Families disagree. So the game is already ambiguous. Now add a ladder from 7 back to 14. Follow every jump, and you go round forever.

So where do you catch it? Skip validation, and a player finds it. Mid-game is too late to fix a board. The fix is a board rule, not a play rule. The Board constructor refuses it. No game ever sees a bad board.

The rule: no jump may end where another jump starts. And here's the bonus. A cycle needs a chain. So that one check bans every cycle too.

The demo builds three broken boards. A snake on 100 would steal a win. Two jumps starting on square 4? Refused. And our chain: ladder 4 to 14 ends where another jump starts.

Each refusal comes with a message a level designer can fix. Validate on construction. An invalid board can't exist. So the game never has to check for one.

Full breakdown in the lecture.