Without the shield or mask, 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.
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. However, you may 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 or mask of reflection even if you kill Basilisks from a safe spot.)
The name "Basilisk" comes from the Greek word "basilískos" (βασιλίσκος), which means "Little King".
The fact that a player needs a Mirror shield to fight Basilisks is derived from the European legend of Basilisks, which had the power to cause death with just a single glance and were reputed to cause an unwanted death to themselves if they saw their reflection.