There is no unied theory of game design, instead designers
are limited to collections of principles and best practises.
Jesse Schell presents in his book The Art of Game
Design 100 of such principles. Limited research has been
conducted in order to explain these principles, but a lot of
studies have been conducted in the eld of children psychology
in order to understand what play is, why children
play, what impact play has on the development of children
and how good play is established. In this master thesis I
have tried to explain the lenses of Jesse Schell through
theories of children's play. By starting with a comparison
between play as described in child psychology and games
as described by Schell, I have accounted for how the lenses
can be explained and supported by theories of children's
play and described what this new perspective on game
design principles can add to the use of them. It turns
out that many of lenses can actually be explained and
supported with theories of children's play and this thesis
serves as the foundation for a deeper scientic research of
the principles. Along with the examination of the lenses
I have developed a Breakout game to demonstrate some
of the lenses. The game contains various versions of the
same game; one basic version containing only the core
mechanics and several others each demonstrating one of
the lenses