How does surprise affect AC?

Question

Under wrestling rules, the Grindhouse rulebook tells that everyone involved in wrestling is attacked as though they were surprised.

Under Encounters, in the surprise section, there is info on how to determine surprise, but it does not tell how surprise affects AC.

How does surprise affect armour class?

Answer 1

A quote from near the end of the grindhouse book, in the guidance for filling the character sheet (page 166):

Surprised AC is Mêlée without shield or Dexterity modifiers, minus 2.

Also, as nitsua60 points out, halflings get a bonus to armour class when they are not surprised.