In more detail, the land of Ethnos contains twelve tribes of fantasy creatures, and in each game you choose six of them (five in a 2/3-player game), then create a deck with only the creatures in those tribes
A patent was granted to Wizards of the Coast in 1997 for "a novel method of game play and game components that in one embodiment are in the form of trading cards" that includes claims covering games whose rules include many of Magic' s elements in combination, including concepts such as changing orientation of a game component to indicate use (referred to in the rules of Magic and later of Garfield's games such as Vampire: The Eternal Struggle as "tapping") and constructing a deck by selecting cards from a larger pool
Whether its saying (or screaming) certain words (as seen in some of the previous entries) so that an ability triggers or can be activated or having to do some kind of physical interaction with your card, Un-sets are very fond of these kinds of mechanics
Bent Spoon is a Pokmon Tool with this effect: Bent Spoon - Item - Pokmon Tool Prevent all effects of your opponent's attacks, except damage, done to the Pokmon this card is attached to
Prices are updated based upon YuGiOh 2015 Mega-Tin Mega Pack listings that sold on eBay and other marketplaces