A long time ago, in a town far, far away (away from anywhere, trust me), I used to play BECMI, then AD&D. At the time, when playing a magic-user, especially at low level, combat basically went like this: you cast your few spells (usually Sleep, Magic Missile or Charm Person), then you switched to throwing daggers for the rest of the day.
This house rule aims to reskin the dagger-throwing or sling-using magic-user a bit, hopefully without making him too powerful but making him feel like a wizard nonetheless.
Getting a magic wand
At creation time, a magic-user gets a magic wand for free along with his spell book. The character is assumed to have built the wand during his apprenticeship.
The wand is 30 to 50 cm long, most often of wood or ivory but can be of any mundane, non-precious material. Detect Magic shows it radiate a faint enchantment dweomer in AD&D2, or just detects it as magic in AD&D1.
The magic of the wand is attuned to the character and it cannot be used in any way by anybody else.
If the wand is destroyed or otherwise lost, the character can enchant a new one. He will need components worth 100 gold pieces and building and enchanting the wand will take a full week of work.
Using a magic wand
So, what can this wand do? Basically, I want it to be a more magicky version of base projectile weapons.
The magic-user can use his wand as a missile weapon with a range of 6” (AD&D1) or 60 yards (AD&D2). The attack is rolled as a standard ranged attack, with no range penalty. It does 1d4 damage points on a hit.
The bolts launched by the wand can be fire, frost, lightning or stone (bludgeoning). The player chooses the energy type once and for all at character creation, it cannot be changed later, even if the character builds a new wand.
If the player wants a different type of energy, this can be worked out with the DM; just avoid “pure magic” (what D&D5 calls force damage). For instance, a necromancer could use withering bolts which can damage any living creature but are useless against undead.
If the target is immune to non-magical damage, it gets a saving throw vs wands to avoid taking damage.
What about illusionists?
In AD&D2, illusionists are just a variant of wizard so the general rule applies.
In AD&D1, illusionists can choose a different energy type for each attack with the wand. On the other hand, all targets can make a saving throw vs spell to deny damage. This saving throw replaces the saving throw vs wands that creatures immune to non-magical damage normally get.
OK, I have not play tested this rule, as I have not run AD&D for more than 15 years. But if I play it again, I will definitely try this.