Just happened to be browsing through the EfU website info on game mechanic changes.

It listed Mage Armor as being changed to +4 AC. Wouldn't that be equivalent to Shield, except for a longer spell duration and a lack of protection vs. Magic Missile?

I'd also like to make sure I understand what +4 AC means... I'm assuming it means that any armor, bracers of armor, and/or amulets of natural armor worn would not stack, but that any other AC bonuses would?

Will Shield still stack with Mage Armor?

Thanks in advance for the clarification.

Mage Armor gives +4 Armor AC, essentially equivalent to wearing chain for instance. This won't work if you're wearing any kind of leather/metal armor or have bracers.

Shield gives +4 deflection AC, which won't stack with other forms of deflection (i.e. rings of protection).

Shield and Mage armor will stack.