The Staff of Guthix is a magic item that is one of the most powerful weapons in the game. It can be crafted from two sheets of balanced metal and a wither star, placed diagonally in a crafting table. The staff allows the player to become invincible for around 40 seconds by right-clicking. In this state the player can withstand any amount of damage, allowing them to undertake otherwise impossible feats such as swimming through lava.
