Necromancer noob Question

[Noonien]

Hi all !

My group is now lvl 2, yes, hurray :)
Our wizard decided to take the path of a necromancer.
1st of all a general spell casting question:
Every Wizard can cast every spell from any school, so for example a School of Illusion wizard can also cast necro spells , but the spells of a specific school are more effective if you also have choosen the appropriate school, right ?
So for example every wizard can cast "animate dead" but a necro can cast this spell more effectively, is this right ?


Regarding "Grim Harvest":
So this is just a passive ability, coming into work every time when the wizard kills a mob (not undead or construct) with a spell lvl 1 or higher? Nothing he needs to tell before the kill, so like "Hey great and beautiful GM, I will use grim harvest when I kill this foe this round" ....so its always present ?
The wizards need to do the "final strike" on the mob, so if he only hurts a mob and someone else kills it, he does have no benefit ?

[Ecks]

1. A wizard can learn and cast any spell from the Wizard spell list (PHBp114). The spells must be of a level for which the wizard has spell slots. Some abilities specific to the School of Necromancy (e.g. Grim Harvest) will have additional benefits when casting necromancy spells.
2. You have it right, but note that Grim Harvest only works once per turn, and the wizard must kill the creature. If using a Necromancy spell, more hit points are regained.

[LordEntrails]

Wizards can only cast spells they have prepared. They can only prepare a certain number of spells from their spell books (level + Int bonus I think). They only get so many spells they can add to their spell book (unless they find more as treasure).

So, unlike a cleric that can prepare any spell from their spell list, a wizard has to have it in their spell book.

[GavinRuneblade]

So for example every wizard can cast "animate dead" but a necro can cast this spell more effectively, is this right ?
No. Wizards get no advantage when casting a spell from their school unless another ability specifically says they do. This is important because many wizards don't specialize in a single school, instead they are from different traditions like the Bladesinger in Sword Coast Adventures or the War Mage from Xanather's Guide to Everything.

So what does a necromancer get?
At level 2:
Necromancy Savant: the gold and time to scribe necromancy spells into their spell book is halved.
Grim Harvest: Heal when you kill using necromancy spells

So if the necromancer rises to level 5 and casts Animate Dead it is no different at all when the necro casts it compared to when an illusionist casts it because neither Necromancy Savant nor Grim Harvest apply. But look at 6th level:
Undead Thralls: Target on additional corpse, increased hp, and add proficiency to attacks.
Now animate dead is better when the necro casts it than when the illusionist casts it. But finger of death is not. It is still exactly the same when a necro casts it and when an illusionist casts it because none of the necromancer's abilities apply until someone dies and then grim harvest triggers.

[Noonien]

Thanks a lot all, understood :)