“…The adaptation may be achieved through the modification of game scenarios, game world entities, difficulty levels, graphic user interfaces, etc. (see for example (Peirce et al, 2008;Chittaro et al, 2009;Rojas et al, 2012)). For instance, Hunicke et al (2004) proposed an adaptive system called Hamlet, in which the strength of weapons, the virtual level of health, accuracy and other game entity properties are adapted to the player's skills.…”