Ammann organizes his monsters into several broad categories ("Humanoids" from goblinoids to githzerai; "Monstrosities" from ettercaps to krakens; "Celestials" from angels to pegasi; etc) and then proceeds from a set of basic premises: every creature wants to survive; physical abilities define fighting styles; intelligence determines tactical nous; wisdom determines self-preservation instincts; etc.
Each monster is then given a set of tactical notes that nudge DMs into creating combat encounters that are different for every kind of adversary, with explanations of how the monsters will roleplay as well, creating a springboard for some really rich play.
This is a massive and ambitious project that I'm frankly in awe of. A companion volume, Live to Tell the Tale: Combat Tactics for Player Characters, will come out in June, is aimed at players, rather than DMs, and explains how to use combat as part of your role-playing.
Like all good RPG sourcebooks, The Monsters Know What They're Doing is a hoot just to read, and transported me back to my days of poring over the Monster Manual and the Fiend Folio. I can only imagine how much fun it is to play a session with a DM who's using it to guide their work.
The Monsters Know What They're Doing: Combat Tactics for Dungeon Masters [Keith Ammann/Saga Press]
