The Book a Month Challenge theme for June was knowledge, and I chose to read the new fourth edition Dungeons & Dragons Player's Handbook. I think it counts. I packed this along on our trip and read nearly all of it before we returned home.
I'm pretty pleased with this new edition. I had been skeptical, because 3rd and 3.5 editions were not released that long ago and I feared a money-making ploy. However, 4th edition is significantly different from the prior versions of the game, introducing an entirely new system for character powers and customization. It's very well thought-out, and more elegant than 3rd edition. Combat still works the same way, for the most part, but the new edition streamlines and clarifies many aspects of the old system. Skills have also been streamlined, but feats have been expanded and changed - many of the abilities granted by feats are now part of the class powers, so these new feats are less powerful and you get then more often as your character progresses in level.
There are a few new classes and races which always spices a game up. I've just rolled up a half-elf warlord, one of the new classes. I'm very much looking forward to seeing how the new edition plays out over time.