From the GW2 User Agreement:--- start paste ---You acknowledge, and further agree, that You have no IP right related to any Account ID, any Account Display Name, any ArenaNet Message Board ID, any communication or information on any ArenaNet Message Board provided by You or anyone else, any information, feedback or communication related to the Game, any Character ID or characteristics related to a Character ID, any combination of the foregoing or parts thereof, or any combination of the foregoing with any Service, Content, Game, or parts thereof.--- end paste --- Would it be generous and a good faith act for Anet to "give" something to the player who brought something like this to production? Sure, but they are certainly not obligated to do so, nor is it plagiarism.