This is not a playtest review.
Assassin is the first in Mongoose's Power Classes series, offering a new class which can be taken from 1st level.
Assassin comprises 16 half-A4-size staplebound pages, cut vertically in the same manner as AEG's Adventure Keep modules. At $2.95, this is a very high price per page (AEG's Adventure Keep modules were $2.49 at the same page count). The inside covers are used for credits and OGL but, unlike AEG's Adventure Keep modules, information from the back cover is reproduced on the first page. Font size is good, margins are average (but due to the format are effectively doubled compared to an A4 size format) and there are a couple of instances of white space. The fourpieces of mono internal art and the colour front cover are fairly average. Due to the nature of the content, the writing style is pretty mechanics-driven - what isn't mechanics-driven is fairly good. Editing also seems good.
The first half of the book is essentially a new 20-level class, the Assassin. The layout follows the standard template set by Core Rulebook I. The assassin, as can be imagined, tends to be of evil alignment, but must be non-good. He has a d6 hit die but half the skill points of a rogue. BAB and save progressions are the same as a rogue, and the assassin also gains the rogue's sneak attack ability, though it is enhanced to do twice the amount of damage if an assassination attempt is made after studying the victim for three rounds or more. He also has the potential to perform a variant of the death from massive damage effect with this attempt. The assassin is also skilled in poison use and can gain bonuses to certain skills if the assassin has studied the location where he will attempt the assassination for at least six hours. The assassin also gain an exotic weapon proficiency every six levels from 6th level.
The second half of the book introduces two new types of poison - the loyalty egg (a slow-acting poison fed to a victim whose 'loyalty' is then assured by giving him small amounts of the antidote which staves off the effects of the poison for a limited time), and poisons that replicate the effects of the diseases from Core Rulebook II to mask the real poison. The next section offers three types of rings that administer poison by drip, needle, or squirt, and the accessory ends with a number of new weapons suitable for an assassin such as a blowgun, garotte, and stiletto. There is also a sidebar offering a mechanic for concealing weapons using the Disguise skill.
Conclusion:
This seems a fairly balanced 20-level class, and would not be out of place among the other core classes. The poisons and weapons add a nice touch and I liked the use of the Disguise skill to conceal weapons. The value of the accessory will be dependent on whether you (or your GM if you're a player) feel happy letting assassins into your campaign as a character class. And whether the low price outweighs the high price per page.