Weapons/Implements: (max 2 points) 2 points if a single weapon or implement can be used for both classes. 1 point if there are limitations, such as only a specific magic item or items working (e.g. Rogue/warlock gets 1 point because a pact blade will work for both classes).
Ability scores: (max 3 points) 2 points if the multiclass has a primary stat which matches with either a primary or secondary stat of the main class. 1 point if the multiclass has a secondary ability which matches either a primary or secondary ability of the main class.
A primary score is one which is used for attacks and damage for many of the class's powers. A secondary score is a score which is mostly used for class features and secondary effects of powers. Please note that in the case of the wizard, dexterity is so insignificant that I do not consider it a secondary score.
By Asmor - Asmor.com - Encounter-a-Day