  As a contribution to the challenge of building game-playing AI systems, we
develop and analyse a formal language for representing and reasoning about
strategies. Our logical language builds on the existing general Game
Description Language (GDL) and extends it by a standard modality for linear
time along with two dual connectives to express preferences when combining
strategies. The semantics of the language is provided by a standard
state-transition model. As such, problems that require reasoning about games
can be solved by the standard methods for reasoning about actions and change.
We also endow the language with a specific semantics by which strategy formulas
are understood as move recommendations for a player. To illustrate how our
formalism supports automated reasoning about strategies, we demonstrate two
example methods of implementation\/: first, we formalise the semantic
interpretation of our language in conjunction with game rules and strategy
rules in the Situation Calculus; second, we show how the reasoning problem can
be solved with Answer Set Programming.
