If a wizard has Necromancy spells then he is allowed to choose his spells. This is quite different from other wizards who are dealt spells randomly.

If only one side has Necromancy spells then the player can choose his spells and distribute them to his wizards as he wishes.

If both sides have Necromancy spells then the highest level wizard chooses his spells first, and then the lower levels, rolling off for those of equal potency.

In the case of some Undead wizards the number of spells they have is not the same as their magic level. This is shown on the chart below together with the maximum number of magic items they are permitted.