Explain a Confusing Board Game Rule Using Your Last Game as the Example

Everyone had a different interpretation and the rulebook wording did not help. This explains the actual rule using your specific situation as the example, tells you what should have happened, and gives you a way to remember it so the argument does not happen again.

Explain this board game rule using a real situation from my last game as the example, not the abstract rulebook wording:

Rule: [paste the confusing rule text here]
What happened in my game: [describe the specific situation where the rule came up and confused someone]

Tell me plainly what should have happened, why the rule works that way, and one memorable way to remember it for next time.