Haste: Speeds the Wizard up by Dark And Darker Gold a pretty noticeable amount for a short duration. This is the key tool Wizards use to always keep their opponents at range, and using this they can outrun just about anyone in the game (outside of projectile weapons or other Spells).
Invisibility: One of the best Spells to use on Wizard, but only veteran players seem to be utilizing it to the utmost. Basically allows the Wizard to use the same strategies as a Rogue does with their Hide ability.
Fireball: The Spell everyone uses at first, tends to show up in every game, and is almost always incredibly good. But, in Dark and Darker, players will quickly realizes that it is easy to hit allies with and there are better options for overall damage.
Chain Lightning: Likely the best option damage-wise, and the friendly-fire aspect of it is a bit misleading (doesn't actually chain to allies like it says it does). When aimed properly, can decimate an unaware foe.
Magic Missile: The most iconic 'Wizard Spell', Magic Missile, is incredibly good in Dark and Darker as well. It's great for NPC enemies, good for area denial in a PvP fight, and it's the best Spell to use if the enemy manages to close the distance as it can quickly melt through their HP before their swing connects.
Last-Second General Wizard Tips
Dark and Darker - Artwork From Presskit Showing A Party Exploring With A Wizard-1
And that's pretty much everything players need to know about building Wizards in Dark and Darker. This class, out of Dark And Darker Gold Coins all the classes the game currently offers, is probably one of the most challenging ones to play for a newcomer.
The Wall