I assume that armor provides any defense value for a player character if such armor has a defense value. Is there any other factor that provides a defense value for a player character (not a creature or NPC)?

Tang86 said:

I am relatively new to reading WFRP3e, but I am pretty sure the answer is no. Defence is really a measure of a person's passive ability to make a hit harmless (like AC). It isn't an active defence which is covered under the seperate cards.

The only source of defense for a PC is armor + shields. The way to get additional dice to help you defend yourself are the active defenses: Block, Dodge, and Parry which you use when attacked.

Pretty sure troll slayers have a defense value of 1 while not wearing armor..could be wrong.

Lazer Knees said:

You're right, the troll slayer career ability gives extra defense when not wearing armor.

Lazer Knees said:

I believe their Career Ability is that they have 1 Defense Value for each Slayer Career, but for the other Careers, all Defense Value comes from armor.