What the fuck is a spell level? In the context of DnD what are

It's relative power scaling. Not 100% perfect so you might find 2nd level spell that's actually more potent than 3rd level spell but generally the higher the level the more potent the spell.

>What metric is used to determine this?
Either there's some complex formula or game makers just eyeball it.

>>50765036

Basically they measure the difficulty to resist spells, since the save DC is tied to the spell level. Not so in 5e, I think, but I've never played it.

Since most spells don't really have comparable effects (How do you measure the difference between a spell that animates a rope and a spell that lets you talk to animals?), game designers mostly eyeball the relative difference in power and sometimes things like difficulty to cast.

>>50765097
this.

you can look at it like the progressive nature of learning more complex skills - learning to do a handstand = gymnastics level 1 maneuver, while walking around on your hands is gymnastics level 2 or higher.

take spells like lesser restoration and greater restoration as examples also.

>>50765036
Purely a game mechanic. It does not have any correlation to anything within a setting, and moreover shouldn't for the sake of everyone's sanity.

>>50765325

But some spells require components equal to the level!

Those are material components that you need to know a specific number for!

A gameplay abstraction that woefully fails at its goal of balancing magic.

>>50765147
Spell level in 5e has become more of a balancing thing, I'd say that spell level is supposed to be an abstraction of the difficulty to cast theses spells, and only thtough growing more experienced in similar, lower lever spells do you learn how to use higher level spells or eek out more uses of the spells you currently know.

>>50765325
but wands can't store spells greater than 4th level