Brassican Mages have low Defence, so melee or ranged is advised. Magic is not advised as they are resistant due to their high Magic level. Because a player cannot pray against a Brassican Mage's attack, having plenty of food before the fight is essential, especially if encountering it via the strange device as it damages the player after every use. Wearing high Magic defence armour such as Karil's or black dragonhide will help defend against its attack. It is recommended to use a weapon with a strong special attack, such as a Dragon dagger.
Although protection prayers do not work against them, it can be useful to use defensive prayers such as Steel Skin to increase your overall defence. It is even more useful to use Piety or Rigour (depending on combat style) to increase both your defence and your melee/range stats.
Wearing rings of recoil or a charged ring of suffering is useful in deflecting some damage back onto the Mage. Low level players might want to try poisoning the Mage and hiding behind an obstacle.
For Brassican Mages fought in the Wilderness, bring a clue box and items you are prepared to lose. The fast, typeless attacks can deal a lot of damage very quickly, so it is very easy to die in a short period of time.
Drops
Drop rates estimated based on 1,771,328 samples from the Drop Rate Project, unless otherwise cited.
The Brassican Mage's dialogue "Die deliciously!" is a reference to the 2015 film The Witch.
References
^Jagex. Mod Ash's Twitter account. 2 March 2020. Archived from the original on 15 August 2021. Mod Ash: "[How is the Brassican Mage's attack roll calculated, and what defence style does it roll against?] Standard magical accuracy roll against your magical defence."