Guide:The Twins strategies

"This is going to be a terrible night..."

The Twins are the Hardmode version of the Eye of Cthulhu. They are part of the trio of the mechanical bosses, alongside with The Destroyer and Skeletron Prime.

Spawn Condition
The Twins can be spawned by fulfilling any of these conditions: It must then be defeated before the night ends.
 * Smash a / . They will then have a 10% chance of appearing when night falls. Note that this condition is shared with the rest of the trio, and thus it's not guaranteed if they have yet to be defeated, and will only work if The Twins have yet to be defeated;
 * Use a at night.

The Fight
The Twins, as the name suggests, are two separate monsters, both of which must be defeated. They have a combined health of 0 /, shared between them. Retinazer, distinguished by its red iris and that it fires lasers. Spazmatism, distinguished by its green iris and that it fires cursed flames.

When reduced to 2/5 health, they will transform, gaining a slight boost in offense and defense. Only one Eye will transform; both must be reduced to 8,000 and 9,000 respectively for each to transform. When one is destroyed, the other will continue attacking in the same pattern.

It's a good idea to take them out one at a time, because if one dies first, it will be much easier to defeat the other one.

Retinazer
In its first form, Retinazer will fire lasers at the player at a steady but somewhat slow rate. This is occasionally interrupted by charging attacks, which mirror that of its partner. Retinazer does slightly less damage than Spazmatism, but this is offset by its higher accuracy thanks to the speed of the lasers. When not charging, Retinazer will always be aligned diagonally with the player, positioned above them.

When it changes into its second form, it will no longer engage in charge attacks. Instead, its lasers will progressively fire at a faster rate as it loses health. This is occasionally supplemented by a weaker but much more rapid laser attack that tracks extremely well. To avoid this, try to fall as fast as you can, and you can be left unscathed. With wings it is possible to "zig-zag" up and down to dodge the lasers. This is made trickier as the fight goes on, with Retinazer using more rapid and fast lasers that are much harder to dodge.

Spazmatism
Spazmatism, like Retinazer, varies between firing Cursed Flames from a distance and engaging in charging attacks. The flames do more damage than the lasers, but are not as fast and thus easier to dodge. However, the Cursed Inferno debuff can be very dangerous for its high damage over time and its ability to stop health regeneration. Its charge attacks are faster and more agressive than Retinazer.

Spazmatism's second form changes his attack pattern dramatically compared to Retinazer. Its cursed flame attack becomes a constant stream of flame, which will last for several seconds (and deal large amounts of damage). However, it does not chase the player quite as quickly as it does in its first form, making avoiding the attack somewhat easier. Once it stops spewing flame, it will charge with greatly increased speed, which also does a lot more damage. Dodging these charges is quite difficult. Much like Retinazer, fall as fast as you can while he is charging, and you should be okay. Misdirecting Spazmatism's charges is easier than it sounds; if you jump as he slows down, he will charge over you. This causes Spazmatism to charge at you from either above or below, making him easier to dodge if you just run.

Which to Defeat First
The following lists shows Pros and Cons by defeating one of the Twins. Players generally kill Spazmatism first.

Defeating Retinazer first:

Pros: Retinazer has a ranged attack, and defeating this Twin first will assist players who are bad at dodging, afraid of lasers, or have a relatively low movement speed.

Cons: Retinazer has many, many lasers to dodge, and, in addition, if you are a slow player, defeating Retinazer can be the more difficult of the two Twins to fight.

Defeating Spazmatism first:

Pros: Damage from Cursed Inferno can easily add up, so if you defeat him first, you won't have to deal with that for as long. Keeping Retinazer in its first form can allow you to easily heal to full before killing it.

Cons: Attempting to defeat it as either a slow or melee player (unless you have a melee weapon that shoots a projectile like the Beam Sword or the Ice Sickle) can make dodging the eye fire more difficult.

Terrain preparation
The Sky above the surface is highly recommended for the Twins arena, as vertical movement is required to dodge most of the attacks.


 * A very long Sky Bridge (if possible made out of or ) is optimal. Continuously running with // causes both to miss you with their projectiles very often, and keeps each Twin at a stationary horizontal position most of the time, allowing you to fire continuously at it without switching your aim. Wings will help dodge each of the Twins' second phases. Using Asphalt can negate the need for Boots, while using them can allow you to avoid taking damage completely. However, try not to run too fast if you use Boots and Asphalt, as Retinazer may fall behind and despawn. Spazmatism, however, is fast enough to keep up. Regular stone blocks can be used too if you have obtained the.
 * The standard Boss arena of several layers of Platforms may be of use, as it allows firing and maneuvering in any direction. A solid ceiling just above your top platform will block Retinazer's beam attacks, as Retinazer always flanks from above.
 * Also, a wall on both sides of a small area can block Spazmatism's cursed fire, but be careful not to run out of time from covering behind the wall. It is helpful to have a one block hole one block up to shoot through. This is more useful if you want to try tanking the boss with the above tip of heart statues. If you can tank the hits with the help of heart statues, you can gun down Retinazer while Spazmatism is only able to charge at you.
 * A safety box in the ground isn't bad either, if you acquired the . That way you could attack Retinazer while its laser can't hurt you in the box. In order to attack Spazmatism make the box one block from the surface and bring, the impact from the stars could hurt it. Stay close to the edge so the Cursed flames can't hurt you.
 * You can also use when building a sky arena to avoid the Twins attack while doing a ton of damage with ranged weapons.

Gearing up
If you already defeated at least one of the Mechanical Bosses, you can explore the Underground Jungle for 20. These will increase your maximum life to 500, which can help to defeat the rest of the Mechanical Bosses.

Armor

 * provides the greatest overall increase to all stats. Melee and ranged users should substitute in a to increase damage output and defense without sacrificing anything important.
 * is a great choice due to its also high stats and the buff.
 * provides very high critical strike chance and its set bonus can hit multiple parts.
 * provides lower stat bonuses, but the greatly increases natural regeneration.
 * becomes a great choice if you have already defeated a Mechanical Boss.
 * is the best choice for summoners. However, it is unwise to rely on summons unless you have prepared a large area with background walls to aid the mobility of spider minions.
 * and provide weak stat bonuses, but allow you to mix different damage types.

Weapons

 * For Melee users:
 * The  shoots very fast and deals a lot of damage per dagger. It also inflicts, which deals 15 damage per second, more than any other debuff available. If aimed right, it can manage to hit both eyes at the same time.
 * could also be used, as Spazmatism will spend most of the time behind you, so shooting constantly backwards with the piercing projectile will hit him multiple times and deal quite reasonable damage.
 * Alternatively, can work too, if you already defeated The Destroyer.
 * with the Yoyo Bag, can be useful.


 * For Ranged users:
 * The or  with   or  is the optimal weapon for players who have yet to beat any Hardmode boss.
 * such as the Megashark, Uzi, Gatligator, and Clockwork Assault Rifle can be quite effective when paired with or.
 * Keeping an on hand is a good idea just in case you run out of ammo.
 * is a great bow, especially if combined with, even better with a , as these three together can take down any of The Twins in seconds.
 * The with Wooden Arrows will be very useful as well, as it turns into, severely hurting the eyes.
 * The with  is an effective weapon, since the darts will usually all hit.


 * For Magic users:
 * is one of the strongest weapons mages can use in early hardmode.
 * The and the  are also very powerful choices.
 * The is a highly damaging weapon that is also consistent thanks to its homing properties.
 * The can also be very strong, despite its short range.
 * If you have Crimson, a good idea is the get the, which is highly effective as it increases the damage greatly thanks to the , even when not used.
 * It's nice to have a, since the clouds can deal a good amount of damage if used properly.


 * For Summoners :


 * The is the best summoning choice because the spiders will latch on while they change forms doing hundreds of damage.
 * The also is worth running, as it doesn't count towards your total minions summoned.
 * If a Mechanical Boss has already been defeated, the is a powerful choice when facing the Twins.

Accessories
Accessories that improve mobility are a must, since the Twins use quick attacks.
 * The and  are a must, especially for the Sky Bridge method. They allow the player to dodge, and also allow the player to flee temporarily if health is running low.
 * Even though it doesn't prevent Cursed Inferno, the can still be used to prevent Knockback and for some useful extra defense.
 * The same is true for the and the . Knockback prevention is vital when trying to fight the Twins.
 * An of your respective class is a must have in Hardmode because of its big damage buffs.
 * If playing in Expert mode, the is an incredibly useful item as well, with its dash being great for dodging.
 * The Expert-exclusive can greatly reduce damage taken.
 * The provides a helpful boost to newer or slower players taking too much damage by reducing the cooldown of Potion Sickness as well as increasing passive health regeneration, it can also be used by quickswapping it from the vanity slot, since the effect only applies when consuming a Health Potion.
 * The is another good choice, as the frequent charging attacks deal a lot of rapid damage, and the extra period of invulnerability mitigates a significant portion of this damage.
 * The is very helpful if you use Melee, as it will give a minor boost to all stats, raising your defense and therefore survivability, and also giving higher damage.
 * The are helpful if you're using mana consuming items as you will take damage frequently from The Twins.

If possible, reforge all Accessories for damage, crit chance or defense bonuses. If money is no object (see Guide:Making Money), having all Accessories reforged to Warding, Lucky or Menacing provides an extra 20 defense, 20% crit chance or 20% damage (, since the  allows you to have 6 accessories).

Potions

 * , and  will help prevent fatal damage. Two of each will likely cover the entire night.
 * is harder to craft, requiring, but it can boost your health to 480 (600 if the health bar has been maxed out through the use of ).
 * Any food item providing the buff is very useful.
 * can be especially useful, as it eliminates the need for any arena and may free up an accessory slot.
 * helps you evade the twins. Two should last the entire fight.
 * can greatly increase maneuverabilty in midair.
 * If you have access to a world with Corruption, a is a good bonus, but not necessary.
 * For magic users, a and a  are must haves.
 * will greatly boost the damage and speed of Arrows.
 * Melee users greatly benefit from the effects of an or
 * is absolutely vital for Summoners attempting this fight.

Miscellaneous

 * Because the Twins are vulnerable to many debuffs, melee players can take great advantage of Flasks. The greatly increases the damage output of all weapons, and the, , and  can give a very slight increase to .  Similarly, the Spider minions can keep them afflicted with Venom, rangers can use Frostburn or other special arrows, and magicians can use a Poison Staff or whatever other weapons they've acquired.
 * The is useful against Retinazer because the spawned ice blocks can block his lasers.

Close-ranged Unicorn Strategy
A strategy that is helpful for Melee players is a Skybridge using a Blessed Apple and any kind of yoyo (A Yoyo Bag is recommended). Running with the Unicorn and shooting the yoyo behind you will deal a lot of damage and you won't get hit very much as the unicorn is slightly faster. Warning: Using this strategy may lead to the The Twins despawning if you go too fast.

Sentry Farming
After gaining access to the Tier 2 equipment sold by the Tavernkeep, the fight becomes much easier to do. Wearing the Squire armor and using the Ballista Cane will give the best results because of the high defense and health regeneration provided by the armor, as well as the Ballista Panic! buff doubling the firing rate. Acquiring one of the accessories dropped by the Ogre is recommended for this method. When building your arena, be sure to use platforms whenever possible to maximize the opportunities your Ballistas have to fire. Make sure that you have Heart Lanterns and Campfires set up to give yourself the most health regeneration. Having a good pair of Wings, the or its upgrades, and the  or  are recommended for maximum mobility. The will make the fight go much faster, rounding out your accessories. A few are all the healing you'll need in case you get backed into a tight spot. Once the Twins have been summoned in, simply kite them around your Ballistas, taking damage periodically, preferably from Retinazer's laser for minimal damage. With the best Modifiers on your gear and all the relevant buffs, the Twins will go down in two to three minutes. If you find yourself taking too much damage and needing to heal more, consider swapping out the Summoner Emblem with a so you can heal more often.

Invincibility Machine
Warning: Many players will consider invincibility machines as cheating.

After beating up the biome Biome Mimics, you should have and. With two and a block overhead you can make the invincibility machine. Get a and try to bounce on both dummies while keeping it rapid. After you summon the boss, use the Fetid Baghnakhs to quickly take out Spazmatism. Then use the Daedalus Stormbow to beat Retinazer.