LotR being a cooperative but also competitive game, I prefer people to come out of the closet and claim they have played any battle before time rather than have them do it with nobody being the wiser...

I understand that it is best not to do it to keep a bit of surprise to the game but there is no way to enforce a ban on such conduct so I think it is better to allow it but keeping the results to PM or spoilers is best, so as not to runin other's people's game...

Just my