Cultural Enforcement
Cultural Enforcement is an informal game term. Cards with cultural enforcement require you to play them as part of a deck that focuses on their culture, either directly or indirectly, by referring to race, Unique character name, or keyword closely associated with a particular culture. These requirements usually take the form of spotting, exerting, or only working on a character of a particular culture. The more requirements, the strong the enforcement. Denethor, Lord of Minas Tirith (10R28) is an example of a card with very strong cultural enforcement, since he has to spot two other Gondor men to be played, and his ability only works on Gondor culture cards. On the other hand, Legolas, Greenleaf (1R50) has very weak cultural enforcement, since he does not require any other Elven cards to function.
Cards with weak cultural enforcement are often splashed into decks focusing on another culture, or used as part of a Rainbow deck.