Any project that's been prebuilt by someone else and distributed or sold to the general public for the purpose of building off of it to make your own game.(Typically those would have something like the basic controls for character movement or a turn-based system you need for a card game.)
Those would be allowed, but you must disclose the template you used when submitting your game and you could be disqualified if it's not far enough away from the original project. 馃憤
