A Basilisk is a Slayer monster that requires a Slayer level of 40 to kill. Like cockatrices, players must equip a mirror shield when fighting these monsters. Players require 25 defence in order to receive basilisks as a Slayer assignment, as 25 defence is required to wield the shield.
Without the shield, the player's stats will be greatly reduced, and the player will take damage frequently, even if a safe spot is used. Protect from Melee/Deflect melee can reduce damage from the attack, as it is still a melee attack, but the stats will still be lowered.
Weaknesses
Basilisks are weak to air spells, so it is advisable to bring some air runes, a good wand, and decent magic armour. Players with level 70 defence or above will not get hit very often, so less food is recommended to make room for drops, but you will get hit a somewhat large amount, particularly if you are not using magic. A suggestion is that if you bring Guthan the Infested's equipment, you can go to the next door chamber to fight and heal. The spell Bones to peaches is highly recommended for lower levels. The Pollnivneach Slayer Dungeon has many safe spots created by rocks in the floor. It is also possible to safe spot them from the south in the Fremennik Slayer Dungeon the eastern wall near the south entrance. (NOTE: You still need a mirror shield even if you kill Basilisks from a safe spot.)
Locations
Fremennik Slayer Dungeon (Multi-combat area, like the rest of RuneScape due to the Evoloution of Combat Live update; Players can not use Dwarf Multicannon in this dungeon.)
Pollnivneach Slayer Dungeon, after defeating the Basilisk boss (Multi-combat area; Players can use Dwarf Multicannon in this dungeon.)