Guide:Eye of Cthulhu strategies

Terrain and Gear


Like all Bosses, preparing for the fight is probably the biggest factor in your success:

When fighting the Eye of Cthulhu, a strategy I've always found to work is to make an arena of Dirt Block or Stone Block and place wood platforms every 6 blocks so that you can evade the Eye by either running, jumping or dropping.

Arenas with walls on either side can limit your horizontal movement, but will also provide a backdrop for shuriken and bow users to easily pick up their expended ammo for reuse during the fight. Lots of platforms can provide greater mobility, but will seriously hinder the effectiveness of most ranged weapons as many types of ammo cannot travel through them. Balance is the key.

Good Armor is recommended for this fight, because even though the boss doesn't hit very hard, he summons a lot of Servant of Cthulhu and can be rather hard to dodge for the new/inexperienced player.

Weapons
Because of all the servants this boss summons, weapons with a piercing attack are extremely useful. An effective weapon to take are shurikens, a stack or two is more than enough to defeat this boss with relative ease, other weapons to take would be a bow with Flaming Arrows/Unholy Arrows for the high damage. If you have the money to spare, grenades can be used. Because the boss is a flying type, melee weapons are limited in use.

No matter what the weapon of choice, weapons with higher damage per second are preferred. The greater your damage, the shorter the fight and the better your chances of survival.

First Phase
During this phase, the Eye will, for a large majority of the fight, float around above you, summoning Servants to fly towards you and kill you.

A good strategy in this phase is to aim ranged weapons at the pupil of his eye, since that is where he spawns the Servants. That way, you can kill the servant and damage the eye. If you stand directly below the Eye and aim straight up with a piercing weapon, after a few seconds your projectile will fall back down and hit the Eye again.

Second Phase
For the last half of the fight, the boss turns into a massive, flying, eye-mouth... thing. It'll charge you 3 times, and then wait a few seconds during which you can nuke him.

Survival
Unlike other bosses, the Eye of Cthulhu will flee if the player dies while fighting him. It will also flee if the player fails to defeat it before early dawn (about 4:30am, if you're wearing a watch). The best way to avoid this is, like the other methods described above, a matter of preparation. Start the fight early after sundown, take lots of potions with you, and wear the best gear available to you.