FrogReaver
The most respectful and polite poster ever
What would you say about the 1 lvl dip in cleric and 1 lvl dip in fighter? If I do just 1 lvl dip in cleric it will be in the Forge Cleric because of the heavy armor and the blessing of the Forge And I get 1 extra ASI. But If I dip in fighter I can have the knowledge domain and get 2 new skills with expertise. And there's the matter of the Trickery cleric that has a very nice Channel Divinity.
-Do not do a single level dip in fighter in any circumstance. The only real reason to take fighter levels as a wizard is to get action surge.
-A single level dip in cleric is okay but less optimized than going straight wizard because it slows your access to higher level spells.
-If you are already level 18+ and dip a level of cleric I'm not opposed but I also don't think a few points of AC and access to level 1 cleric spells amounts to anything important at that level anyways. So at that point it's just about character concept, why would a level 18+ wizard stop pause his pursuit of learned magic and start worshiping a deity. It's just a very peculiar place to take your first level of cleric and mechanically the benefit is so small at that point.
There are reasons to think about taking cleric levels, but it's not because you can edge out a few extra points of AC at level 18+. Good reasons to play a cleric/wizard multiclass include:
Wanting to be a wizard but feeling your party needs some healing magic.
An interesting character concept.