From the Official Website:Brought to you by the designers of the award-winning Grim Tales, Trailblazer is designed to be fully customizable and compatible with your existing library of 3rd edition settings and supplements. Each section of the work addresses a specific complaint or problem with the ruleset, proposes a solution to the problem, and explains how to integrate each sub-system into your game. Copious designer notes help you fully understand the philosophy behind each change, and empowers you, the DM, to make your own tweaks and changes to get your game running at peak performance.Trailblazer does not present 'change for changes sake.' Every change is a direct response to real problems raised by players in our own games and by the larger gaming community. Trailblazer tackles problems big and small:1. the power curve, the 'accident of math,' and the 'sweet spot' 2. DM prep time 3. CR/EL/XP and encounter design 4. smoother, faster combat resolution 5. class balance 6. multiclass spellcasters 7. overhauling the skill system 8. annoyances like grappling, turn undead, 1-2-1 movement, and attacks of opportunity 9. 'The 15-Minute Adventuring Day' - BoardGameGeek