This could be done with events. Just create a Conditional branch that checks to see what level the player is, if its equal to, or over 100 then the door is open, if it's less than 100, the door is closed.
RM Skill: Skilled
That's not hard a parallel process that check your level and stores it make a Conditional branch on the door If VARLEVEL is greater or = to 100 > Do what you need to make the door thing work >Else >"You need to be at least level 100 to enter." You don't really NEED a parallel process either When the player interacts with the door the first thing it should do is a variable operation: Plrlvl= Hero's level Then use a conditional branch to determine whether the door opens or not. Should look like this: If Plrlvl = or is Greater than 100 >(door opens) >Else >Message: "You cannot enter this room until you are level 100"