Guild Wars 2

Perhaps someone here that sees/knows something I do not can enlighten me; but why is it I can open some loot chests/bags but not others, and use for instance an Experience Booster but not a Celebration Booster while in sPvP (after joining an Unranked Arena match)?
I’m seriously struggling to find the red thread here..

Guess everyone is equally confused then.. :P

I think it’s the classification of consumables. It’s the same for other gamemodes. Some are blocked in different areas. While I don’t know the exact background my best guess is, that for instance the Celebration Booster has not the same classification as the exp. Maybe celeb is some kind of buff food or transformation or whatever (by coding) and therefore it is blocked in matches. It doesn’t always make sense