Turtle Helmet
6% increased melee damage Enemies are more likely to target you
6How to craft it
Mythril AnvilUsed to craft
Set bonus
The bonus applies while the helmet, chestpiece and leggings are all worn together.
what the set bonus really is
Turtle is a defensive melee set built from Chlorophyte and three Turtle Shells. Its bonus does two separate jobs: it shaves a flat slice off everything that lands on you, and it throws contact damage back at whatever touched you with enough knockback to launch it across the screen. The reflection hits harder than a Thorns Potion, and neither that potion nor the Dryad's blessing can push it any higher, so what the set gives you is the ceiling.
where thorns falls apart
The reflection only answers contact. Lasers, bullets and every scripted attack a boss throws pass through it untouched, so the effect contributes nothing in exactly the fights you would want it for. It also scales off enemy contact damage, which by this stage is small next to any Hardmode weapon. Banners for the enemy you are fighting quietly cut it further, negative luck can turn the roll against you, and it will not exceed its cap no matter what walked into you.
what it is actually for
The value is being able to ignore things. Weak enemies that only bite kill themselves on your armor while you keep mining or building, and with knockback immunity from a shield they cannot even interrupt you. The set also pulls aggro hard, which is the main reason to wear it in multiplayer. You take the hits your teammates would have taken, and the damage reduction is what makes that survivable. Run it alongside a Paladin's Shield or one of its upgrades and you are absorbing damage for the entire group.
mixing pieces
The chest piece is the only part with offense worth keeping. Wear the Turtle Scale Mail with Squire's Greaves and either a Chlorophyte Mask or a Hallowed Mask, and you get a considerably harder hitting melee build, paid for with both the damage reduction and the reflection. Full Turtle is the tank build; that mix is the fighting build.
what comes after
Turtle mostly exists as the step before Beetle armor, which is crafted out of it once Golem is dead. If you intend to make both Beetle chest pieces, gather the extra shell and bars on the same trip rather than going back to the Jungle twice. In spirit it is the Hardmode version of Cactus armor: heavy on defense, thin on damage, and painful to walk into.