Hi guys! I just had a question pop up that I'm not entirely sure how to answer.

One of my players is a 10th level cleric who's character has been studying the arcane. He wants to start levelling up as a wizard, so he'd probably end up being something like a Cleric (10)/ Wizard (10).

My question is;

As he levels up as a wizard he gains 2 spells per level that will go into his spell book. The description in the Wizard class says

"these spells must be of a level for which you have spell slots, as shown on the wizard table. (PHB page 114)"

However in the multi-classing spell-caster section it says

"Once you have the Spellcasting feature from more then one class, use the rules below (PHB page 164)" 

"You determine what spells you know and can prepare for each class individually, as if you were a single classed member of that class. (PHB page 164)"

"You determine your spell available spell slots by adding together all your levels in... Use this total to determine your spell slots by consulting the multiclassing spellcaster table. (PHB page 164)"

So, when he levels up and learns spells automatically in his spell book, does he use the Wizard level to determine his newly learned spells, or the multiclassing spellcaster table? One would mean 2nd level spells and the other would mean 6th level spells. Just a bit confused.

As a side note, if he is limited by his wizard level, is he limited to lower level spells he finds out in the world or could those be learned using the multiclassing table

The wizards spells he learns would be using his Wizard levels only (2nd level spells). And he could not copy higher level scrolls into his book.

Multiclassing spellcasters is pretty bad in 5e. I usually handle people that want to do that with a custom subclass, similar to Divine Soul and Sorcerer.

Multiclass spellcasters have been pretty bad since 1e, really.  Some kind of theurge class would be a welcome addition to the game, IMHO.

Picking either the Divine Soul Sorcerer or the Arcana Domain Cleric, I think you can get a reasonable theurge within the rules.

I could see homebrewing a second Cleric domain option that focused more on the theurge aspect though.

Quote from nativek >> 

"You determine what spells you know and can prepare for each class individually, as if you were a single classed member of that class. (PHB page 164)"

 

 Does this not answer your questions? The wizard can add spells to their spellbook up to the level they would have if they were not multiclassed.

To make things easier, the DDB character sheets won't let you add spells higher than you should.