From the publisher's website:

The year is 1636 and France is a troubled nation.

A great and terrible evil gnaws at its core.

Darkness stalks the land.

All that stands between chaos and order are the King’s Musketeers.

Explore a France of swashbuckling action, powerful magic, daring deeds, courtly intrigue, witty repartee, and vile monsters! The characters are France’s bravest and proudest defenders, the King’s Musketeers. Pitted against them is a plethora of corrupt nobles, black magicians, fell demons, and twisted secret societies.

Set at the height of power of Cardinal Richelieu and Louis XIII, All for One: Régime Diabolique mixes the action of literary works such as the Count of Monte Cristo and The Three Musketeers with horror and intrigue to create a unique, vibrant setting. The high-action is powered by Ubiquity, an innovative role playing game system that emphasizes storytelling and cinematic action.

Strap on your sword, salute the King, and prepare to fight the creatures of darkness!

All for One: Régime Diabolique Player's Guide give you all the information required to build your character. If you are planning to be the Games Master you will need the full All For One Rulebook. This is a players guide only from Triple Ace Games.