The rulebook PDFs will eventually be released for free to the general public. This pledge level grants you earlier access to the rulebook PDFs than non-backers, but the real (financial) benefit is the various reference pdfs -- which won't be released for free. These include the Druid spellbook, Cleric spellbook, Magic-user spellbook, and Illusionist spellbook, which separate out the spells by character class and present them level by level instead of purely alphabetically without respect to spell level. There is also a short reference PDF for each of the ten character classes, which can be used by the player as an ultra-mini "Player's Guide." Since these contain the class abilities, to-hit tables, and saving throw tables, they are ideal as a reference tool for a brand-new player who isn't confronted with an entire book of rules all at once.