Warren Spector- “Hell no we didn't achieve what we were striving for on Deus Ex. What you do is you aim for the moon so you end up hitting Hawaii or something. If you aim for Hawaii you end up in Keokuk, Iowa or something, you know?”
Shigeru Miyamoto- “What role does realism play in videogames I ask myself. Is this image more interesting? Sometimes.. however, what if a "detailed" hand with 5 fingers is catching a bottle but the fingers pass right through it? Is this still realistic? Rather than to show each meticulous and tiny detail of a finger, it is more important to make the end action look more credible by working on the
movement and functionality of the arms and the hand in relation to the object.”
Sid Meier – “Gameplay is defined as a series of interesting choices.”

Warren Spector's The Rules of Role-Playing
• Always show the goal. Players should see their next goal (or encounter an
• intriguing mystery) before they can achieve (or explain) it.
• Problems not puzzles. It's an obstacle course, not a jigsaw puzzle. Game
• situations should make logical sense and solutions should never depend on
• reading the designer's mind. And there should always be more than one
• way to get past a game obstacle. Always.
• No forced failure. Failure isn't fun. Getting knocked unconscious and waking
• up in a strange place or finding yourself standing over dead bodies while
• holding a smoking gun can be cool story elements, but situations the player
• has no chance to react to are bad. Used sparingly, to drive a story forward,
• O.K. Don't overuse!
• It's the people, stupid. Role-playing is about interacting with other people
• in a variety of ways (not just combat… not just conversation…).
• Players do; NPCs watch. It's no fun to watch an NPC do something cool.
• If it's a cool thing, let the player do it. If it's a boring or mundane thing,
• don't even let the player think about it -- let an NPC do it.
• Have you patted your player on the back today? Constant rewards will
• drive players onward. Make sure you reward players regularly. And make
• sure the rewards get more impressive as the game goes on.
• Players get smarter so games get harder. Make sure game difficulty
• escalates as players become more accustomed to your interface and more
• familiar with your world. Make sure you reward the player by making him
• or her more powerful as the game goes on.
• Think 3D. A 3D map cannot be laid out on graph paper. It has to take into
• account things over the player's head and under the player's feet. If there's
• no need to look up and down -- constantly -- make a 2D game!
• Are You Connected? Maps in a 3D game world must feature massive
• interconnectivity. Tunnels that go direct from Point A to Point B are bad;
• loops (horizontal and vertical) and areas with multiple entrance and exit
• points are good.