Arcane Guardians are bosses from Gemcraft Chapter 0 who defend the Gem of Eternity.

There are 2 ways of meeting an Arcane Guardian:

- Arcane Guardian levels

- Arcane mode

There are 5 Arcane Guardian levels throughout the game, each of them starts off as a normal level although the smaller infested buildings are replaced by Arcane locks which will destroy your Wizard Tower if you don't throw a grade 3 gem bomb on them in time. After all the monsters are killed and all the Arcane locks are destroyed the Guardian emerges from the main infested building with a few Arcane Minions appearing from the sideways. The Guardian has a huge armor level which can be cut down by killing the minions and is immune to a certain gem effect (poison, slowing, freezing etc). After beating an Arcane Guardian level for the first time the player is award a Journey amulet.

Arcane mode can be played after finishing any normal field after reaching wizard level 64. The only differences with an Arcane Guardian level is that the Guardian does not come with any Arcane Minions and has no immunity to any gem effect.