Is there a spell or cantrip to manipulate metal?

Question

I am curious if there is a spell or cantrip to manipulate metal. I'd like to be able to turn someone's armor into a cage or extend my blade. Maybe there'd be certain limits such as the spell level influencing the amount of metal and or quality/number of types.

Answer 1

Spells to manipulate metal objects

Unfortunately I think there is no cantrip currently in the game that does exactly what you are looking for. Durable transformation is hard to come by in 5e, and objects worn or carried by creatures are -- with exceptions like heat metal below -- also difficult to affect, probably to avoid cheap an cheesy ways to rid opponents of their weapons, armor and magic items (for example, not even the mighty meteor swarm can damage or set worn or carried equipment on fire). The main spells to manipulate metal objects I'm aware of are:

• Mending, Cantrip: can repair minor damage, including metal
• Heat metal, level 2: Nasty offensive spell against someone in full plate, without saving throw, deals damage to someone in contact with metal
• Shatter, level 2: damage nonmagical objects, possibly destroying them. Does not work on worn or carried objects.
• Enlarge/Reduce, level 2: make any object larger and heavier, or smaller and lighter, including metal ones. Does not work on worn or carried objects.
• Fabricate, level 4: Turn raw materials (including metal) into something manufactured. Does not work on finished goods like armor, but can handle large amounts of material.
• True Polymorph, level 9: Polymorph any object into a creature, which you then can turn into another object with another casting, works permanently (until dispelled). Again does not work on worn or carried objects.
• Wish, level 9: can do anything with the DMs buy-in (risk of losing the right to cast it, with unusual applications)

In addition, the School of Transmutation wizard has a feature on level 2 called Minor Alchemy, that allows you to turn one substance into another, and works on iron, copper or silver. The effect ends after one hour or if you stop concentrating. On level 14 you gain the Master Transmuter feature, that can use up your transmuter stone to effect a Major Transformation:

You can transmute one nonmagical object—no larger than a 5-foot cube—into another nonmagical object of similar size and mass and of equal or lesser value. You must spend 10 minutes handling the object to transform it.

While that would work on an object being worn and carried, the 10 minutes of handling means that you'll practically not be able to use it in combat on an object that is controlled by an opponent.

If you want to put someone into a cage, the Wizard level 7 spell forcecage is pretty much tailor made. It is very good, not requiring concentration. Just be aware that creatures with teleportation abilities can get out.