Spells in Noita are organised into tiers which dictate which spells can spawn; each biome selects one or more tiers of spells and wands to spawn when generating spell shops and wands. Most spells belong to more than one tier, though it may define a different rarity value for each tier (for example, a spell may be very common for Tier 1, but exceedingly rare in Tier 3). Wand generators pull spells from one tier lower, so a tier 3 wand will have tier 2 spells in it for example.
Spellshop tiers are set by the depth they appear in, unless they are forced to spawn spells from a specific tier. Most early biomes force a specific tier. Vault and Temple spellshops are set by the depth. Any spellshop deeper than Temple will be tier 6. Hell and Sky force spells to spawn from tier 10.
Spellshops can spawn any type of spell, but wands can only spawn with multicasts, projectiles or modifiers. This means that material, utility, static projectile and other type spells can only be found from spellshops, secret rooms or chests.
↑Pre-made wands are unique from other wand spawns in the game as they can spawn with static projectile spells like Circle of Thunder and utility spells like All-Seeing Eye. There is an 88% chance that any given Mines wand is a pre-made wand; the rest are random Tier 1 wands.