Trespass to land

Tort

If A wants to steel some artifacts from a hotel, from couple B in room x. Do they commit the theft when they enter the hotel or when they enter b's hotel room. Much help appreciated

When they enter the hotel room. They only trespass (and thus commit burglary as they have the MR) the moment they enter somewhere they have no permission to be. People are generally allowed to wander into hotel foyers. But when they leave the foyer, that may be trespass if the hotel doesn't allow non-guests past a certain point. Otherwise it's in the room as they definitely have no permission to be there.

This is a tort question so mens rea and burgulary dont play a part. If they enter the hotel with the intention to steel then does the tort take place when they enter the hotel or the room?

Nope - trespass is a tort of strict liability. Intention has no part in it.

Sort of. Except that intention is relevant here, because entering the hotel is prima facie a trespass, because the land belongs to someone else. The defence to that trespass is the implied consent of the owner/occupier i.e. an implied licence to enter. But that implied licence would almost certainly not be construed as extending to someone entering for the purpose of stealing. And therefore someone entering the hotel intending to steal therein almost certainly commits the tort of trespass to land as soon as they enter the hotel.

Whether it is worth the hotel suing is another matter - if no damage is done to the hotel, and the property taken belongs wholly to guests (who will have their own claim in conversion against the thief), damages are unlikely to be large.