You’d think that you wouldn’t have to tell a Wizard this, but it’s important to know what your magic spells do. If you select Illusory Wall when you really needed to cast Hallucinatory Terrain, your pointy-hatted spell-spinner may have a short adventuring career in front of him. Wizards of the Coast, every aware that the Dungeons & Dragons rules can never be written clearly enough to satisfy everybody, has dedicated seven webpages worth of clarification on spell descriptions. It doesn’t actually describe the spells, but rather goes in-depth into what kind of information you should be getting out of the spell description entries in the PHB and elsewhere. As we’re coming to expect from the Rules of the Game series, it is quite thorough, and I recommend it for anybody with a burning desire to be even more of a rules-lawyer than I am, or anybody suffering from insomnia. Enjoy!