The last of the first three classes presented in the oD&D Little Brown Books is the magic-user. The D&D arcane caster has always been a hodge-podge of literary inspiration, primarily a heavy modification of the spellcasters presented in Jack Vance’s The Dying Earth series: casters who can “memorize” a number of magical formulas in their heads which are “lost” upon casting.
The class has went through three distinct names: magic-user, mage, and wizard. No other class has had its terminology changed up so much, although Fighting-Men became Fighters, and Thieves became Rogues. On the other hand, whatever their name, wizards have stayed very much the same. They are the weakest class, in both physical health and martial prowess. They can’t wear armor, can’t use most weapons, and are otherwise the weakest link in the party (in that they die the easiest).
At the same time, they’re the strongest link in the party, and are on a steady track to become the most powerful. They have always made up by being the artillery: mages are the guys who drop the flashy damage spells, who control the battlefield with de-buffs and movement restrictions, and who get the most powerful abilities at high level in the form of 8th and 9th level spells. Nobody else got spells that powerful.
Specialist wizards have existed since AD&D, with the quintessential gnome illusionist. Illusionists gained minor bonuses at the cost of having a different spell list and slightly fewer hit dice. 2nd Edition codified this; instead of having a separate spell list for each specialist school, each school had prohibited “opposing schools” that the specialist wizard couldn’t access.
Wizards had also gotten some secondary rules benefits to represent their higher intelligence, which is reflected in how many skills 3.x gives the class. The other major change was metamagic feats: the ability to “modify” a spell by casting it at a higher level spell slot. These can increase the spell’s effects, or allow the caster to cast the spell without requiring verbal commands or movement components. Specialists saw some loosening of their rules, in that a specialist chooses their restricted schools.
Pathfinder did much to change how the wizard operated; their hit die increased, and specialists now got specialty powers and spells related to their school ala Cleric domains. 0-level “cantrip” spells could be cast at-will, and specialists got a large number of per-day abilities, allowing the wizard to cast minor tricks through several encounters. The spell list also saw some nerfs, making the class less powerful in the low-mid range of the game. 4th Ed put the Wizard in the Arcane Controller role: much as with all other wizards, the 4e version focuses on doing multi-die damage to multiple targets, de-buffing enemies, and altering the terrain to handle movement control.
Intelligence has always been the arcane caster’s attribute of choice. Constitution (for health) and Dexterity (for AC) have always been good secondary choices for Wizards, though they don’t really require any secondary attributes.
Role within the party
The mage is the glass cannon artillery of the party: the class nobody wants to see killed because of its potent spellcasting abilities. Its spellcasting falls into three main categories. First, damage; wizards get better damage-dealing spells than anyone else, particularly ones that can affect multiple targets (fireball, cloudkill, cone of cold). They also work great at de-buffing powerful enemies (ray of enfeeblement, glitterdust for invisible things) or just simply locking them out (sleep, hold person, charm monster). Lastly, they handle all sorts of battlefield control to tie up the enemy (web, grease, black tentacles).
The wizard’s spell-casting is more diverse than that; they’re also great at summoning, can buff allies, and have all sorts of other utility spells from feather fall to telepathic bond. They can divine the future, transform targets into dragons or newts, wish for anything they can imagine, and stop time itself. The wizard has always started the game as the person cowering behind the armored meat-shields, and ended with unlimited power potential at their fingertips.
Wizards have great skills and skill points, a nice selection of metamagic feats, and a great spell selection. They also have a familiar, which can be used as a lookout or spy, though having a familiar die is a serious issue. Perhaps their best advantage is their spells, particularly those which can keep them alive long enough to control the battle: mage armor, mirror image, stoneskin, and fly should be mandatory for all arcane spellcasters. The ability to modify them with metamagic makes them very potent, as does the freedom to prepare from a wide array of known spells.
Oh, and they can also make their own magic items. Let that sink in for a minute.
Their spells aside, wizards are a horribly weak class. They have the lowest health and bad Fort and Ref saves. Without sinking feats into armored arcana, the possibility of spell-casting failure means they can’t wear armor. Between the low health and low AC, wizards are incredibly fragile things; a few solid hits or a crit can end the wizard before they’ve even begun to cast. Their low attack bonus should be a deterrent to getting up close and personal in combat combat… at least, until the wizard can prepare transformation and their horde of personal defense spells.
Probably the biggest disadvantage is the wizards’ low number of spells per day. While their casting is more versatile and customizable, sorcerers get the same spells, and more of them, at a slightly slower progression. Picking and choosing spells and scrolls carefully is a must, otherwise the wizard is left with nothing to do be rely on wands or crossbows.
The wizard is the least useful class in pure martial combat, and it has the lowest survivability in low-level and even into mid-level adventures. But its spell-casting makes it the obvious superior class. Many of its spells simply avoid or finish combat: sleep or color spray for groups at low-level; dominate or hold/charm for solo enemies at mid-levels. At the end of the game, they get wish and time stop, and no other class has anything which comes even close to these abilities. The wizard gets better offensive spells than the cleric or druid, enabling them potentially better damage output than the fighter. And there’s always something for a wizard to do.
The wizard also one-ups to sorcerer from its ability to customize each day’s prepared spells to fit specific adventures—fire spells against trolls, water breathing for aquatic adventures, etc. A sorcerer has to make do with what they’ve got at all times, but if the wizard has eight hours of forewarning, they can prepare the right spells the night before heading into combat. While the sorcerer gets more spells per day, unless they choose their list very carefully, the wizard is the better option every time with its unending spell list.