If the wrong number of builds are posted for a player then the following is what the GM will implement:-
1. Firstly, as with all other mistakes, if it isn't spotted before the next movement phase is posted then the error stands.
2. If the GM had counted correctly and the player was responsible for ordering the wrong number of builds then any shortfall in the number stands until the next build phase; if too many were ordered and allowed then the correct number from the beginning of the player's list will be allowed and others removed.
3. If the GM made an error in the count then any shortfall can be made up by the player once it is realised, and any excess builds will be lost from the end of the ordered list as in 2.
In each case, once the error is spotted there should be sufficient time for the player to make a decision (in 3.) and for other players to react to it before the next deadline.
In forming this rule GMs pointed out that it is the responsibility of the player to check the GM count!
