Game Transformations and Game Equivalence Boudewijn P. de Bruin In 1952, Thompson defined four transformations on extensive games, and proved that they leave the reduced normal form intact (a so-called "adequacy" theorem). Kohlberg and Mertens, in 1986, proposed two additional game transformations. In this paper, I will state and prove adequacy results for all six transformations in a uniform manner. Then, a number of well-known solution concepts will be surveyed. Finally, I will examine the (in)variance of the solution concepts under the game transformations, so as to determine whether they induced a plausible notion of game equivalence.