@JeremyECrawford @mikemearls If a character multiclasses into wizard, how do you handle not having a Spellbook immediately? The PHB says you start with 6 level 1 spells in your Spellbook, so do you not have any spells at all? Do you prepare what you can and transcribe later? #DnD
— Trae Block (@BlockTrae) April 9, 2018
The wizard's Spellcasting feature says you have a spellbook with six 1st-level wizards spells in it of your choice. That means you have a spellbook with those six spells in it. Work out with your DM how you acquired that wondrous book. #DnD https://t.co/zmPtj10GOg
— Jeremy Crawford (@JeremyECrawford) April 9, 2018
Assume the choice of becoming a mage involved finding and understanding a spellbook with the requisite 6 spells..
Does a cleric who multi-classes into fighter and gets heavy armor proficiency automatically get full plate? No, he has to buy it, just like the multi-classing new wizard should have to buy his own spellbook.
A cleric multiclassing into fighter doesn’t get proficiency with heavy armor anyway, unless they started as a fighter or started as a cleric who gets heavy armor proficiency to start with, and then chooses it as part of their suggested starting gear.
I get what you’re going for, but your analogy is a bit off.
As Jack noted, which I second, your analogy/comparison is very flawed in this regard. The wizard’s spellbook is a part-and-parcel feature included in the class listing, unlike with (as exampled) any specific armor. To put it another way: the ability to cast spells is a class feature for wizards just as proficiency for (plate, we’ll say) armor is for a fighter; however, unlike with a fighter, a wizard’s class feature indicates that they *have*/possess this item as part of the class feature. As JC notes, it’s up to the DM and player to work out when/how the player, specifically, obtained this book… but he doesn’t have to “pay” for it, as such. It’s a class feature and the in-narrative story point is simply adjusted/hand-waived accordingly. (That is, perhaps the character receives it as payment for services-rendered by a wizard — one who sees promise in the character’s ability to use magic; alternately, it could be something the nascent wizard comes across in a horde or library and after having a “revelation/awakening” finds himself on a path to study wizardry, with the initial cantrips/spells provided via the mechanical/class feature simply representing that those were the spells he found and/or he had a natural affinity for them and “groked” them very quickly. Either way, the narrative and the mechanics are then balanced and in-sync.)