First, let me say up front; this is my first review. I've read several, both since finding RPG.net and immediately before writing this one; hopefully, I'll avoid any awful blunders.

Second, let me say- again, up front -that I have not been a traditional fan of Guardians of Order's flagship product, Big Eyes, Small Mouth. Nor a particular fan of the d20 system as a whole.

You can imagine my suprise when, while wandering through my friendly local gaming store, I flipped casually through Slayers d20. And was startled by the number of really interesting ideas presented, as well as how closely the conversion clove to the original source material without completely demolishing the groundwork that d20 works upon.

As a description, the book is printed on non-glossy paper in black and white. The formatting is a simple two collumn affair, and the vast majority of the art are scenes from the Series. It's almost always revelant, as are the periodic quotes. No outrageous spelling or grammar errors, so rock on edittor guys!

The Good

• Magic ROCKS! The magic system presented in the Slayers d20 may be the single best reason to pick up the book, for both a fan of the series and simply someone looking to mine ideas.
  You don't forget spells when you cast them. Instead, casters make a Fortitude Save (with some additional level, attribute and feat bonuses, and most spellcasting classes have Fortitude as a primary Save), with the DC determined by the Spell being cast. Pass or fail, you'll suffer some minor damage; normally, this is non-lethal, which recovers very rapidly.
  Fail this check, though, and you're in a world of potential pain- first, the drain from the spell is likely much higher, and (if you fail a somewhat easier check), the spell may not go off at all. Usually, a failed spell just means no mojo happening, such as Slyphiel's Flare Carrot- but it can involve more Bad Stuff than that. The effects are left intentionally vauge, to encourage GMs to play with spell failures as best fits their series.
  Additionally, there's a LOT of reasons for spellcasters to work together. The effects of spells can stack, casters can work to gather in casting the same spell to both have an additional bonus on the checks and to share the drain. There's also a few ways to individually make spell casting easier, such as loudly declaring the name of the spell, or pausing to recite the full incantation of it.
  I cannot emphasize it enough. The magic system just blew me away. It's a perfect fit for Slayers, and can serve as an excellent source of inspiration for any other game which has a personal energy drain oriented view of how magic operates.
• Psychological Warfare If variety is the spice of life, then Slayers d20 has brought us into the garden with Psychological Warfare. Using it, you can Taunt opponents into acting irrationally, or befuddle and confuse them. It works as per normal for d20- a Resisted skill vs saving throw (with an additional bonus for character level), and several of the new Feats introduced modify the details of how the system interacts with your character.
  It's an excellent idea, it looks well implemdented, and very in keeping with the canon of the show. Additionally, it provides a useful role in the party for the Noble, or other primarily Face-type characters.
• Chimeria and Copies and Dragons, oh my! Character Creation is extremely well handled for the most part; the revamped Classes are all very right feeling; in particular, the Warrior class gets a nifty trait- a Style bonus. It adds a +1 to (their choice when they take it) their to hit, to damage or AC when fighting in a particular style (one handed weapons, sword and shield, unnarmed, etc). This serves as an excellent way to help differentiate between different fighter-types.
  More personally impressive is the integration of both Beastmen races and the bizarre mixed things that sometimes get staring roles in the original series. Slayers handles Chimeria like Zelgadis (a third each of human, demon and rock golemn- don't ask) as a series of racial templates. And they open the door for Dragon PCs- although the Dragons of Slayers aren't quite Council of Wyrms level in power, they're nothing to sneeze at.
• Original Character Stats As a brief note, but one that made me very happy to see, stats for- not only the main cast, but virtually every named character who shows up in the first three seasons are provided. And the main cast are presented with three seperate stat blocks, one for at the end of each season. Such information is highly informative- it helps having Lina to compare yourself to on the scale of 'Badass wizard
• GMing Advise The Slayers d20 book never looses sight of the fact that it is a roleplaying game, and that it's trying to emulate a sometimes dramatic comedy series. It frequently provides advise on how to bring out the funny, adventure design, and so on. Nothing spectacular, but a solid and consistant effort.

The Not as Good

• Content Inclusion, Part I: Color Middle In the middle of the book, roughly seperating the chrunchy of the mechanics to the more fluffy in depth examination of the original series is a set of 14 pages of full color pictures from the series. While they are very pretty, I would have prefered if the book had been either a full fifty dollars and solid color with glossy pages, or if these pages had been omitted and the book's price dropped a bit. While all pretty, they're more what I'd go to an offical artbook for, than a roleplaying supplement.
• Content Inclusion, Part II: Episode Guide Maybe it's just me, but I imagine most people who purchase the Slayers d20 Roleplaying Game are more than passingly familiar with the TV series. However, a good 16 pages are an episode by episode summary of the first three seasons (Slayers, Slayers Next and Slayers Try). This should have been handled as either general plot arc descriptions (which could cover all three seasons easily in two pages, tops), or more elaborately, with illustrations of plot hooks and ways to use similiar events.
• Drama (Points) are Missing So, maybe I'm just spoiled by Buffy and Adventure!, but I fully expected a Drama Points system of some sort to appear. Slayers is a series that cries out for such a mechanic, and it's absense felt odd. And, while it's easy to add such in oneself...

The Bad

• Poorly handles Magic Items
Slayers features one of the major Protagonists relying heavily on a magic item to retain his narrative equality with the rest; that is, Goury (although an expert swordsman) wouldn't be nearly as important to the series if he didn't have the Sword of Light. Further, we later see another character with a weapon of similiar power show up- who is also an expert Swordsman- Zangulus, and the Howling Sword. We even see the Howling Sword shattered- and when Zangulus next appears, he has it again. Apart from these, few characters rely on magic items. Potions are rarely imbibed, scrolls are not read aloud from, and there are remarkably few boots of levitation for a world so soaked in magic that magical item pawn shops exist.
This a round about way of saying that the Slayers d20 RPG fails to properly catch the genre nature of both powerful magic items, and the actual mundanity of anything without a name. No guidelines are given for the creation of such powerful items. Indeed, in the case of the Sword of Light, many of it's more unique features (such as the ability to magnify and catch spells) are left almost entirely to the discretion of the GM.
• REALLY frigging high DCs The DCs on even very basic spells is in the 20s, and they advance by 5s. Drain starts at 1d6 and rises. For a starting PC, magic is much more dangerous and risky than it should be; and even Lina will only outright successfully cast a Dragon Slave about 3 times in 20 (Though she'll rarely fail the control check). I'm inclined to simply chop 10 off the DCs of the the spells outright and lower the Drain by 1 die type (so it starts with a d4 and rises to a d6, then a d8, then wraps to 2d4, and so on), to both bring them more in line with the level of danger and difficulty magic seems to have in Slayers.

It should say something that my bads are such nitpicks; those are the areas that I will be houseruling for my campaign, that startled me by their lack of inclusion. Nothing jumped out as 'bad'. Perhaps playtesting will change my mind- but for the moment, the Slayer's d20 RPG has me deeply impressed and leaving a strong recommendation for folks to get a copy of their own.