There are some classic (meaning so simple they were around way before modern computers and fancy graphics) games and puzzles that can give you a chance to test your reasoning skills. In all of these games, problem solving can be described as state space search. At each move, you must choose from a fairly small (by the standards of living in the real world) set of legal moves. Since any complete solution is a sequence of such moves, one way to think about finding a solution is to think something like, "Suppose I choose A first, then B then C, will I win?" Or, of course you could try, "Choose A first, then B, then D." And so forth.

There are two important things if you want to solve problems like this reasonably efficiently:

• Most importantly: Try your options systematically so that you don't waste time trying redundant paths and you don't miss promising ones.
• Use whatever constraints are available to rule out some paths without actually having to try them all.

Try these. Remember the goal is not just to get an answer but to get one in as few steps as possible. Think about what you're doing. Can you write out reasons for choosing the moves you choose?

• Mastermind
• Wolf, Sheep, Cabbage
• 15 puzzle
• Tower of Hanoi. For a discussion of an algorithm to solve this problem, see also Cut the Knot's page.
• Cryptarithmetic
• Minesweeper: You can play online or download a version to play offline.