Tome of the Mads Gods is an 18-page PDF from Clockwork Golem Workshop (that last page, of course, is the d20 License). It is written by Peter M. Ball. It can be purchased for $1.35, and is just over 300k in size. The product contains no artwork, though to call it totally black-and-white isn't correct, as it has small blue lines bordering the top and bottom of each page. Bookmarks link to every section of the file, including each of the twelve new spells, and both appendices. It is a rather pleasant surprise that the entirety of the text in this work is declared OGC on the last page.
The Tome of the Mad Gods is a spellbook written by a mad dwarven archmage. He, looking for a path to godhood, found a plane of existence where gods are imprisoned in a forced slumber for learning secrets that even divine beings shouldn't know. After some study, he created a dozen new spells from what he learned there, and bequeathed it to a library, from whence it vanished. This is all covered in the History section that the product opens with.
The next section after the history gives us the details of the Tome itself. The information here is impressive in what it covers. Not only are the Tome's appearance and page count given, but also its stats (hit points, hardness, etc.) as well as results of a Knowledge or bardic knowledge check. Also, the entirety of the spells contained in it are laid out. While some DM's might find this somewhat restrictive (since they may want to add their own "forebidden knowledge" spells to it), this is easily circumvented, since the Tome is a massive work, with room for more spells.
The spells themselves all follow the theme of planar forbidden lore. Each of them deals with madness or planar issues in some way. While some of these spells are quite cool (such as mad god's doom, which shows a victim the horror of the Mad Gods' thoughts, reducing their mental ability scores to 1), others seem somewhat uninspired, such as the planar bastion spell, which is very nearly the exact same spell as the genesis spell from the SRD; both create a personal demiplane. Of the dozen new spells, over half of them seemed thematically the same as an existing spell or ability that I've already seen from WotC. Of course, most of those from WotC aren't OGC, and these ones are, so that is a plus.
Appendix 1 is a one-page description of the Realm of the Mad Gods. This outlines the plane where these gods are trapped, giving us the full planar description. While brief, it does manage to convey the basic nature of the plane. However, no mention of any particular locations or inhabitants makes the description feel rather spartan; the Manual of the Planes gave us at least one location for the Far Realm.
Appendix 2 is five pages of planar rules. Almost verbatim, these are the rules of planar traits from the SRD, including planar energy traits, alignment traits, physical traits, morphic traits, and more. While this does help put the traits of the Realm of Mad Gods into perspective if you've never looked up planar traits before, I couldn't get over almost one-third of the product being a reprinting of rules that are already in the SRD. While possibly handy as a reference, it still doesn't seem worth the space; an expanded description of the Realm of Mad Gods, or perhaps a listing of adventure seeds for what to do with the Tome, would have been much more worthwhile for the space used here.
Ultimately, I gave this product two stars. The product has merits that made me want to rate it higher: First, the product ad is honest in what it tells you, saying exactly how many new spells you get, and that five of the pages are rules references. Secondly, the price of the product here is cheap enough that you really can't claim you didn't get enough for your money. There is enough material here to make the purchase worthwhile, but that seems to be despite the presentation, not because of it.
However, although I feel it's more than a 2, it's not up to being a 3. Beyond the issue of how original the spells don't seem, or how brief the Realm of Mad Gods is, is how there are some errors that are fairly noticeable. For one thing, the title on the first page of the product says "Tome of the Lost Gods" instead of "Tome of the Mad Gods." While that's nothing too major (even Monte Cook made a similar mistake, when the first release of the Book of Eldritch Might was titled the "Book of Eldritch Magic"), it does cause one to have some doubts about the product. Likewise, there are some spelling and grammar errors that crept in also. Even a few of the spells have some errors in them; deranged flesh says that casting shapechange on the victim temporarily lifts the effects of the spell...but shapechange is a personal-targeted spell. Likewise, voice of the lost is basically a sonic fireball that also causes the victim (if they fail their save) to have seizures...but no duration for the seizures is given.
All in all, I wanted to give this product a 2.5 rating. It accomplishes what it sets out to do, but doesn't seem to put any effort into doing so, and that can be felt in the text. While Tome of the Mad Gods has ideas that inspire, these are found only by sifting through the rest of it.
