I've been using Enchantment, because the school used to be Enchantment/Charm back in AD&D and did more than just mind affecting magic. However, I think this is a good point and will probably switch to it for general magic items. Specific items will still have specific magic types, however.Well, given that spells like magic weapon have been presented as being Transmutation spells in 3rd Edition and 5th Edition, I'd say Transmutation.
do we make a thread on what a better idea for magic would be?The Wizard schools are inconsistent. Some are purpose, some are means, some are process. I find the schools less helpful to meaningfully organize spells.
Abjuration is a purpose − protect (shield, dispel, restore, etcetera). Healing seems like it should be a form of Abjuration. Abjuration might magically enhance Armor to defend.
Conjuration is a process − makes something out of nothing or relocates. Could make magic items suddenly appear. Could make constructs and force fields like Shield, etcetera.
Divination can foresee the future, thus make armor avoid attacks, weapons strike unerringly, also attack from a remote location, and so on.
Enchantment is a means − the mind. Could make items terrifying to debuff hostiles, or distract targets to attack them more easily.
Evocation is a means − elemental energies, could make various weapons and armor, such Frostbrand, Fireshield, etcetera.
Illusion is weird − it is a means, also the mind like enchantment, but sometimes is quasi-real like conjuration − could make quasi-real armor, blur effect, invisibility, phantasmal weapons, etcetera.
Necromancy is a theme − could be ghostly weapons and armor, necrotic weapons, becoming incorporeal, etcetera.
Transmutation is a process − and can mean anything and everything. Anything that "changes" including every spell, is transmuting. In the sense of transmuting elemental substances (like soil and metal) can fabricate weapons and armor, and enhance their material strength, modify their properties, and in the sense of shapeshifting can form natural armor, claws, and so on.
Pretty sure it's easily refutable.How to "Enchant" an Item
<Transmutation1: Open: Gonna make this sword a magic weapon>
<Abjuration: Open: Hold and protect the following alterations applied to this weapon><Transmutation2>This blade will now be sharper than mundanely possible; +2 to hit </transmutation2><Evocation>Generate Light on this blade<Enchantment>when it is willed in the attuned possessor's hand</enchantment><Enchantment><Divination: Autotrigger><Necromancy: Autotrigger>when within 50' of an undead creature</necromancy></divination></enchantment2></evocation><Evocation><Necromancy>Generate Radiant energy; 2d6 added damage to undead</necromancy></evocation></Abjuration: Seal the protective insulation for alterations applied to this weapon></Transmutation1: Seal the alterations to the weapon>
So, yeah, Transmutation is, irrefutably, responsible for applying and sticking magic on an item.
What magics are actually then stuck with/in the "programming" of the Transmutative processes and incantations is dependent on what the item does/is supposed to do.
Yeeeeah, 'cept no.Pretty sure it's easily refutable.
1e and 2e required both Enchant an Item and Permanency, both enchantment spells.
3e required the spells listed in the magic item itself and minimum spell levels. Transmutation was not required.
4e dunno.
5e Up to the DM, but nothing says it needs transmutation.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.