Jarlaxle's Guide to Traps is a fun collection of dangerous traps to challenge your players as much as your adventuring party! I appreciate the thorough introduction addressing the negative reputation that traps have earned through their oppressive overuse by cruel DMs. This disclaimer is expanded in Chapter 1's "When To Use-" and "When Not To Use Traps" sections. To reiterate the creator's message: respect your players, be kind with your location descriptions when traps are afoot, and everyone will have a great time -- moving on!
The book contains over 50 traps, hauntings, and hazards, as well as useful information on how to design your own traps. Each one indicates the trap trigger, effect, and countermeasures to neutralize the effect. I enjoyed reading Cheap Sh--ty Traps Like Kobolds Use, Switch Cinch (in which an obvious "hidden" switch is itself trapped), and The Doors (a set of massive doors that fall on any character who touches them, resulting in bludgeoning damage equal to a roll of ALL THE DICE THEY HAVE).
The book has a professional and thematic (read: blood spattered) layout; dozens of black & white, old school sketchy art pieces; and an index of headers at the end, but it would be a much more valuable DM resource if it included a standard table of contents up-front to mark the chapters and their sections. Furthermore, readers would greatly benefit from reference tables, and/or a "traps by environment" appendix to help navigate through all the glorious material!
[4 of 5 Stars!]