Rise of the Rune Lords
You gain a familiar.
Prerequisites: Knowledge (arcana) 1 rank, arcane caster level 3rd.
Benefit: You can obtain a familiar arcane bond in the same manner as a wizard (see the wizard class description and the accompanying sidebar, page 82 of the Pathfinder Roleplaying Game Core Rulebook).
For the purpose of determining familiar abilities that depend on your arcane caster class level, your levels in all classes that allow you to cast arcane spells stack.
Adapted from Complete Arcane, page 81.