using puzzle items?

[Enjay]

As I'm sure you have worked out, that kind of thing could be achieved using a script bound to a key to activate an item, rather than the usual inventory system.

This would probably work better with a decorate created item rather than a true inventory item.

Button "X" is bound to a script - if you don't have the item in question, the script returns a "you need to find X" message.

If you do have the item, the script returns a "you're in the wrong place - go to the power room (etc)" message.

If you have the item, and you are in the right place, the script does whatever the item is supposed to do.

All easy enough to do.