Maybe you don't notice it at first, until you inevitably have to take a break. You leave your character idling on the screen as you reach for your tea -- and then you see it. Some tiny detail, a cool little trick that seems deceptively simple until you lean in, squint, and look. Really look. The crumbling cement ruins of Fallout 3 are a pretty good example, with all those bits and pieces nibbled off of their ends. Swivel your camera just a bit and you'll start to unravel that illusion, though, and reveal some clever design tricks where you might have been expecting a highly-detailed model.
Game Art Tricks is a collection of these techniques assembled by Simon Schreibt in collaboration with numerous sources, explaining some of the most impressive effects you may never have thought twice about in many of your favorite games. There's faked fluid movement, surprisingly simple cell-shading, unique uses of parallax, and even some downright mind-bending optical illusions thanks to normal mapping. It's a wealth of information (and animated gifs!) for the idle curious, not to mention a significant source of inspiration for the active creator.