TheCastles & Crusades Players Handbookis the core book for the game. Everything you need to create exciting roleplay, sans monsters, is in the Players Handbook. It is divided into two sections. A player section and a CK section.
In the former are all the rules to create your character for roleplay:
Revised OGL free content
Choose from 13 class, multiclassing & class and a half
Choose from 7 races
Choose disposition, deity if called for, names
Equipping your character
Spells and spell casting
The latter section, the CK section, includes
All the rules for the Siege Engine, the attribute check system
Samples of play
Combat and how to run combat
Game play elements like turning, movement, light and more