Guide:Duke Fishron strategies

Duke Fishron is a tough Hardmode flying boss with very high movement speed and high damage, making it the one of the most difficult bosses in the game. It is advised to use life-draining weapons on him and high movement speed. He can also spawn bubbly tornados as he spins. He has two stages (three in Expert Mode) similar to other bosses

General
If you haven’t restricted yourself to playing with one class this is a simple and effective guide to follow.
 * Make an arena out of Asphalt Blocks (it removes the need for Lightning Boots). It should stretch at least across the ocean. Make it 3-5 platforms high; each platform should be at least 20 blocks away from each other. Leave a gap at either side for maneuver however.
 * Use regenerative Spectre Armor along with the Razorpine if you’ve defeated the Frost Moon. If not, use the Crystal Storm. Make sure to have plenty of high end mana and health potions.
 * The Mana Flower is crucial, as is a shield and high end wings accessory.
 * The Master Ninja Gear is reccommended as well as the Charm of Myths or Magic Cuffs.
 * Try to have most accessories reforged to menacing, warding or arcane.

Arena

 * Make especially sure to build your arena in the Ocean biome. If you fight him anywhere else, he will enter “rage mode”, where he becomes nearly undefeatable for all practical purposes.
 * The arena can usually just be a standard platform arena, however make use of buff stations. The main ones are listed below. If you don’t want an arena you will want a Neptune's Shell and some Wings and keep jumping in and out of the water
 * The boosts melee damage.
 * The Ammo Box lowers ammo consumption for rangers.
 * The Crystal Ball boosts magic overall.
 * The boosts minion capacity by 1.
 * When nearby the player, Sunflowers will boost speed and reduce enemy spawns.
 * Campfires and Heart Lanterns will boost health regeneration of all nearby players. These two stack with each other.
 * The Star in a Bottle will boost mana regeneration.

Armor

 * For melee characters the Beetle armor with Scale Mail are recommended as they give decent defense paired with attack buffs which stacks as the player damages the boss or the Sharknados. If the player desires high defense, Beetle armor with Shell or Turtle armor are recommended.
 * In addition, Melee users may consider using tabi or master ninja gear, as it may save you from Duke Fishron just in time. Also make sure to have a Destroyer Emblem to deal much damage to Duke Fishron.
 * For ranged characters the Shroomite armor or is highly recommended.
 * For summoner characters having both the Spooky armor and the Tiki armor is highly recommended, using the Spooky armor to summon all but the last minion, and wearing the Tiki armor for the additional minion and higher defense.
 * For magic characters, Spectre armor or is highly recommended.
 * For Spectre armor, the set with the Spectre Hood helps with health drain, while the Spectre Mask boosts damage.
 * In the unlikely event that Moon Lord has been defeated, armors constructed from Lunar Fragments may be preferable: Solar Flare armor for melee characters; Vortex armor for ranged characters; Stardust armor for summoners; and Nebula armor for magic or, due to the booster buffs, possibly for any character.
 * Titanium armor, Black Belt/Master Ninja Gear, and Cross Necklace all can also come in handy because of attack dodging boosts, since Duke Fishron's attacks can deal a great amount of damage.

Summoner

 * Due to the ability to always have at least one minion, or two with access to a Bewitching Table, summoning a minion prior to Duke Fishron may be helpful. However, due to his significant defense, weaker minions should be avoided; and due to his extreme speed, slower minions or those who use slower projectiles will be similarly ineffective. The Optic Staff, Xeno Staff, and especially the Deadly Sphere Staff can be quite helpful, where the otherwise impressive Stardust Dragon can have difficulty keeping up with the Duke. The Optic Staff is very unreliable for damage in Expert mode, as the player typically moves quickly enough for the twins to be in their "follow" state and thus deal significantly less damage which can prolong the encounter to a dangerously long time given the stats of Expert Fishron.
 * Maximize summon damage with buffs from food and potions, armor, and accessories when summoning minions, as the minions retain the increased damage even if the equipment is removed, until the minions are unsummoned or replaced.

Magic
If you have beaten Duke Fishron, it is recommended to use the Razorblade Typhoon, as it follows enemies (counters Duke Fishron's high speed) and does high magic damage, as long as you have somewhat decent aim.
 * Homing weapons like Bat Scepter or Spectre Staff will let you focus on dodging.
 * Rapid weapons like Razorpine or Leaf Blower, rapidly recover health when paired with Spectre Hood, which is extremely helpful for the fight. Razorblade Typhoon if you have already defeated the Duke, will let you focus on dodging as well, if you have decent enough aim. The only problem with Razorblade Typhoon is that the homing shots cannot keep up with him when he is rushing.
 * It is possible to outheal Duke Fishron if one has equipped a Mana Flower, A few stacks of Greater Mana Potions (Can get from Wizard) or Super Mana Potions (made from Greater Mana Potions), and a high rate of fire Magic Weapon (Laser Machinegun, Leaf blower, Razorpine, etc.).
 * The Golden Shower spell is helpful as it reduces his defense.
 * If you have good aim the Inferno Fork does a lot of damage.
 * The Blizzard Staff is very good for attacking while he is stationary.
 * Avoid using slow magic weapons like Magnet Sphere, Wasp Gun and Rainbow Gun as Duke Fishron's extreme speed will render these attacks nearly useless.

Melee

 * Vampire Knives are very useful for stealing life combined with decent damage, however the life steal effect seems to work better on his second stage.
 * Flask of Ichor is useful to slightly lower Duke Fishron's defense.
 * The Influx Waver is a better choice if you have defeated the Martian Madness event and obtained it from the Martian Saucer boss.
 * The Terra Blade also performs well, though not usually as well as the Vampire Knives.
 * The Horseman's Blade is also a good choice as its ability to spawn pumpkins works on the bubbles, which there are a lot of. It may not be the best for the whole fight, but it is definitely one of the best against the bubbles because of what you get in return.
 * Constantly throwing the Paladin's Hammer or Possessed Hatchet while flying around can defeat him quickly.
 * A stack of Bananarangs are good against the boss for its rapid throw and return. They do not home in on the boss, so speed is key.
 * The Eye of Cthulhu is the best yoyo that can be used by yoyo users, before defeating the Moon Lord.
 * When Duke Fishron shoots Detonating Bubbles, use Ice Sickle or Death Sickle to clear them.
 * The Solar Eruption is a truly good weapon for the fight (if you have defeated the celestial pillars) with the Beetle armor because of the amazing damage and the small fire debuff it inflicts.
 * Flairon with Beetle armor can kill Duke Fishron in about half a minute, if you have defeated him already.
 * The Scourge of the Corruptor is somewhat low in damage but more than makes up for this by homing in on Fishron during the fight. Paired with a flask or the Fire Gauntlet, the player can focus more on dodging Fishron while the tiny eaters attack and do damage over time. Accumulating a swarm of them before Phase 3 in Expert mode helps do burst damage against Fishron when he's visible.

Ranged

 * The Snowman Cannon is powerful against him, if you have defeated the frost moon. (Very)
 * The Chain Gun, if you have beaten the frost moon, or Megashark, paired with Chlorophyte Bullets do very well; as these bullets have homing properties little aim will be required leaving the player to focus on dodging the boss.
 * The Piranha Gun attaches to Duke Fishron and deals continuous damage, so the player can focus on dodging Duke Fishron's attacks.You must do this at the start of the fight, or else he will be too fast for the piranha to latch on.
 * The Aerial Bane is very useful with its extremely high dps and splitting arrows, dealing damage to the Sharknadoes as well.
 * Ichor Arrows or Ichor Bullets will reduce his defense.
 * On mobile the Clockwork Assault Rifle works well with Chlorophyte Bullets due to its fast fire rate and three-round burst
 * The Chlorophyte Shotbow with Venom Arrows is useful. Chlorophyte Arrows are good, but piercing weapons give the boss a 1/6 second immunity, and the other arrows may not hit him. It's best to use non-piercing arrows, preferably Venom Arrows because of their high velocity. (Note, 1/6 of a second is barely any time, and other piercing weapons are still effective, but that 1/6 of a second is barely long enough to only allow 1-2 Chlorophyte Arrows hit, instead of all five.)
 * The Stynger is very effective.
 * Using a Phantasm with Holy Arrows or Ichor Arrows can make the fight extremely easy, to the point where you can kill the boss within less than a minute and without taking major damage. This will be efficient even without Vortex armor or end-game accessories, although will only be possible if the player has already defeated the Lunar Events (which are considered easier to beat than Duke Fishron by some) to acquire the Vortex Fragments necessary to craft the bow. Tsunami with Holy Arrows also proves to be very effective for farming Duke Fishron.
 * A Tactical Shotgun, or Xenopopper, if you have defeated the Martian Madness event, with Chlorophyte Bullets is good for its wide spread, automatic firing, low ammo consumption, and homing ability.
 * A Venus Magnum with Chlorophyte Bullets works well because of its high DPS and homing ability

Additionally

 * The Rod of Discord isn't a weapon, but helps with dodging, as Duke Fishron's high speed and damage can lead to the player dying quickly.

Accessories
A must is Wings and Lightning Boots or better as primary choice. Though the Lightning Boots are not entirely required, due to you needing to stay in the ocean biome to not enrage. They are both fairly easy to get at this point. If you have defeated Duke Fishron, Fishron Wings will also help. Frog Leg can be used for more mobility. A shield will prevent knockback from Sharknadoes. If you are building an arena of ice blocks, a must have is Frostspark Boots. Equip accessories with damage, critical, or—if using magic—arcane, modifiers. Accessories such as the Celestial Stone, Fire Gauntlet, Sniper Scope, and emblems will also greatly improve damage output. Warding accessories can be used if the player desires extra defense.

If you would rather fight in the water, a Neptune's Shell or any higher tier accessory with the shell can be helpful, as it provides infinite water breathing and "infinite flight" while in the water.

Cross Necklace or Star Veil is recommended as the boss speed might cause several heavy hits on characters should the boss catch the player. The Sharknados may also flank the player hitting them consecutively especially on Duke Fishron's second phase.

Characters with Spectre armor should consider using Magic Cuffs or Celestial Cuffs, as the damage dealt by Duke Fishron's attacks will often times completely restore their MP, allowing them to attack constantly while restoring HP. Care should be taken as the boss' high attack can make quick work of reckless players.

Magic users should also consider the Mana Flower.

If you are using The Eye of Cthulhu or another yoyo, use a Yoyo Bag.

If you have difficulty dodging his charges and/or bubbles, invest some time in getting a Tabi or Master Ninja Gear.

Charm of Myths will both allow for increased regen and reduced time for the Potion Sickness debuff.

The Cosmic Car mount is a good replacement for wings and can be better as it provides infinite air time. However, it may be somewhat slower compared to mid-Hardmode or better wings.

Potions and Buffs
As with any other Hardmode boss, it would be useful to prepare the following potions:
 * Greater Healing Potions are highly recommended, though not entirely necessary with life-draining weapons.
 * Inferno Potion is highly recommended as it will destroy the Detonating Bubbles Fishron spawns.
 * Greater Mana Potions are recommended for magic users.
 * Regeneration Potion and Ironskin Potion to survive. Two of each will last enough.
 * Endurance and Lifeforce potions for even greater survivability.
 * Pumpkin Pies will likely last the entire fight (Well Fed for 45/15minutes), and it's easy to craft.
 * Swiftness Potion helps you a lot to evade the Duke and its attacks.
 * Wrath and/or Rage potions for a boost in damage output.
 * Magic Power Potion and the Crystal Ball's Clairvoyance buff for magic users is recommended.
 * If a player has no arena, they can just use Water Walking Potions.
 * Gravitation Potions can free up an accessory slot, but it's recommended to use Featherfall Potions with them.
 * Melee characters that are good at dodging can use the Tipsy debuff.
 * If you are facing him at night, a Shine Potion, Night Owl Potion, and Hunter Potion will help a lot so that you don't have to worry about visibility.

The Battle
Duke Fishron will attack in three different ways during his first stage. The very first thing Fishron will do is begin his charging flurry. He will charge towards the player exactly 5 times, with a short pause between each charge.

After each charge flurry, he will execute one of two kinds of projectile attacks. The first projectile attack fires around 20 Detonating Bubbles. The second projectile attack will create two small bubbles on either side of where he is that will each generate a Sharknado. The two Sharknadoes are tall and do damage, but they also fire Sharkrons towards the player.

Duke Fishron will alternate between the two different kinds of attacks, in-between charging flurries. When the fight starts, he will charge, followed by bubbles, followed by charge, followed by Sharknadoes.

When Duke falls below 25,000 health, he will stay stationary for a second, then his eyes will glow as he enters his second stage. His damage, and speed increase significantly, however his defense drops to 40.

His charge flurry only has 3 charges, but they are a bit faster than before. He still has two kinds of projectile attacks, but their natures change.

The Detonating Bubble attack now causes him to move around in a circle, dropping the bubbles in a circle around his original location. This spreads out the bubbles, making it more difficult to hit them all.

His Sharknado attack upgrades to summon a Cthulhunado. He will fire a special bubble at you that is quite fast. When it hits you, it will spawn a Cthulhunado, a very tall tornado that does lots of damage and fires large quantities of Sharkrons. It also lasts much longer.

Note that, after the battle is over, care should still be taken. If he has launched a Cthulhunado, it may still fire Sharkrons. He may also have died within the Cthulhunado, so don't charge into it to collect his drops until it dissipates.

Dealing with Charge
Duke Fishron's charging attack is his primary attack, and one of the most difficult to dodge.

The key to dodging it is to try to move perpendicularly to where he is aimed, right before he makes his charge. For example, if you are horizontal with him when he is about to charge, you need to quickly up (or down, if you're already flying). If he is right above/below you, then you need to quickly move left or right.

Another good strategy is to use Beetle armor (If you haven't defeated Golem yet, use Turtle armor), and Vampire Knives. Make a long platform high in the sky as to avoid Sharknadoes, and fly up to space, then drop back down. You'll regenerate life and Duke Fishron will be charging in the wrong place. Fire/Frozen/Leaf Wings and a shield are recommended.

Dealing with Sharknadoes
One important element of the Sharknado attack (just the phase 1 version) is that they will spawn in the location where Duke Fishron was when he fired the attack. And they will despawn almost exactly when he is ready to drop another pair of Sharknadoes.

As long as the player keeps in mind what attack Duke Fishron will do next, the player can put him in a position that makes it hard for the player to hit the Sharknadoes themselves. For example, during the charging flurry before the Sharknado attack, the player can move towards the edge of the screen, horizontally. That way, the player can run the other way knowing that they will not encounter Sharkrons from that direction. This also means that attacks towards Duke Fishron will also be towards the direction of incoming Sharkrons. The player could also construct a skybridge made of platforms in the sky, allowing the player to stay above his Sharknadoes.

Also, note that Duke Fishron's first attack will always be bubbles.

Sharknadoes are quite tall; getting over them will require multiple jumps or some form of Wing.

Dealing with Cthulhunadoes
The upgraded Sharknado attack is a bit more difficult to deal with. It's taller, requiring even more jumps, and it does more damage than the original, plus it fires more Sharkrons.

However, there is one thing that makes it a bit easier to deal with: the Cthulhunado will spawn in the location where you were when the bubble hit you. This gives you a bit more control over where the thing spawns, so you have more of a chance (if you are fast) to make sure it doesn't spawn in an inconvenient place. You likely do not have the speed to outrun the attack, but you can help get it out of the way.

The downside of course is that, once the bubble hits you, you need to quickly move, lest it spawn on top of you.

Another important factor to note is that by no means necessary should you attempt to cross a Cthulhunado. They deal about 100 damage, which will turn the fight in Duke Fishrons favor. Always use Wings/a Cosmic Car Key to fly over them. Alternatively, use the Rod of Discord to teleport to the other side.

Minecart Strategy (without skybridge)
This strategy differs from others in that it doesn't use skybridge, replacing it with looped minecart track above the ocean, so the player won't have to deal with his enraged behavior. It does, however, need some more work than other ones, especially when building arena.

Materials

 * 600-1200 normal minecart tracks for building loop + 2 booster tracks
 * 10-30 Greater Healing Potions
 * Any kind of hammer

Weapons
Ranger: Mage: Melee:
 * Tactical Shotgun, Uzi or Megashark with Chlorophyte Bullets
 * Chlorophyte Shotbow with Venom Arrows
 * Spectre Staff
 * Shadowbeam Staff or Heat Ray
 * Leaf Blower
 * Possessed Hatchet OR Paladin's Hammer
 * Scourge of the Corruptor
 * Vampire Knives

Arena Preparation
The essence is to make looped minecart track approx. 60 tiles above Ocean itself. It should consist of at least 600 tiles; while shape is pretty loose, it should have at least two places in which player drastically changes altitude, as well as at least 100 tiles long flats. One should also make a "Starter" - a short molo with boosters, from which player will summon Duke Fishron and quickly escape to the loop. Placing Campfires and Heart Lanterns could prove to be difficult, but will help player if something goes wrong. It should be noted also that arena shouldn't exceed Ocean biome.

A good arena is a box with two levels, tall enough for you to stand in. The lower level should be empty, except for a one block tall, three block wide, pool of honey. The top level should have a Mimic Statue and a Crab Statue wired to a one-second timer. During the battle, after summoning him, use a Rod of Discord to teleport into the box, stand in the honey, and spawn a bunch of Mimics and Crabs. Use the Horseman's Blade to kill the Mimics and the pumpkins will aim for Duke Fishron.

Execution
When everything's done, player should sit in a minecart on "Starter" and summon the Fishron. As soon as it's done, one should quickly go to loop (boosters will help). At this point, everything that remains is to shoot Fishron while maintaining speed on track, healing a/o replenishing mana when needed. Some tips:
 * Use a homing weapon, especially if your arena is pretty large. Fishron will spend most time off-screen, and high speed will often change directions you're facing.
 * Though stock minecart shouldn't be used, Mechanical Cart is not a good choice. Even though with it provides defense bonus, as well as speed to avoid Fishron's charges, it will probably outrun him so much that he will despawn, what is especially possible on larger arenas. Higher speed means also that you will more often run into Sharknados.
 * Try to make arena consisting of approx. 800 tiles, but don't make it horizontally-long. If you do so, Fishron will frequently run into you, and Cthulunados in his second stage will quickly kill you as there won't be any way to dodge them.

Minecart Strategy (as skybridge; works on 1.3)
Most strategies differ from this one as none of them involve going outside the ocean biome. Although, if one has a mechanical minecart, and a decent ranged weapon, a continuous minecart track from one side of the world to the other with bumpers at the ends, one could outrun Duke Fishron shooting him from a distance. It should be noted though, it is easy to despawn him, and in his third phase he can catch up to you so high defence armor would be recommended for that phase.

"Meat Shield" strategy
If you have 2 or more players, consider having a "meat shield" (A player with Beetle armor w/ Shell and Warding accessories) to focus on dodging and keeping him away. The other player will have Spectre armor w/ Hood, a Laser Machinegun, a Mana Flower and 1-2 stacks of Greater Mana Potions. The defensive player will focus solely on dodging yet staying close to the offensive player, so that the Spectre Hood will heal the defensive player whilst draining Duke Fishron's health

Spike Strategy
You will need a minimum of Hallowed armor with vampire knives no matter your class. You will also need a Cross Necklace or Star Veil. Accessories such as the Black Belt, Celestial Stone, or any emblem will help GREATLY. To top it off you will need some Spikes from the skeleton dungeon. Just sit on the spikes, shooting him with your vampire knives. This works because when he attacks you, your cross necklace or star veil was working from the spikes, which caused only one damage which saves you TONS of health. If you are confident and have killed him before, use the Flairon to kill him in under a minute. This strategy doesn't work in 1.3 or higher.

Anti-Gravity Hook Strategy (only works with enraged duke fishron)
When enraged, Duke Fishron is way faster and does way more damage. But with this stategy, this strength can be turned into a weakness. What you gotta do is get an Anti-Gravity Hook and place one or more platforms in the middle of the air. After fishron becomes enraged, you use your anti-gravity hook in the platform and start using it to spin in a circle. This can make you dodge 100% of the attacks. Keep in mind that this strategy only works with enraged duke fishron, because in his regular behavior he will use sharknados, cthulhunados, etc., and in his enraged behavior he will do nothing but ram you. Then you use the hook on the platform, start spinning and dodge his charges. It can be difficult to hit fishron with this strategy, so it's recommended to use a bullet spam gun with chlorophyte bullets.

Pre-Plantera Strategy
It is possible, although very difficult, to defeat Duke Fishron before fighting Plantera; either for a challenge or for a way to power-up early.

The Gear
The recommended strategy for this fight so early in the game is to use the Megashark with Chlorophyte Bullets, as it has a high damage output and the homing properties of the bullets will make aiming easier as you are moving around the arena. Chlorophyte ranged armor will provide the most defense at this point as well as a good damage boost and some additional damage output from the set bonus. For accessories, the Star Veil/Cross Necklace, and Charm of Myths are recommended. If you do not have enough pink slime to build a large arena, you will need Wings or a Horseshoe as well. The Flesh Knuckles and/or Worm Scarf will help reduce the damage you are taking and Ranger/Avenger Emblems to boost your damage output. A Moon Stone and/or Moon Charm can also help if you fight him during the night, providing defense and regeneration (and damage with the Stone). Having your accessories reforged to Menacing will help with dealing more damage to end the fight faster, but you will need to focus more on dodging Duke Fishron's attacks. Reforging to Warding instead will increase your survivability, but it will take a longer time and more ammunition to beat him.

For potions, a Gravitation potion is critical for this strategy, alternatively you may try with the Pigron mount. Inferno is helpful for killing his bubble projectiles. Lifeforce, Ironskin, Endurance, Wrath/Rage, Regeneration and any food for the Well Fed buff will make the fight easier. Also include a Heartreach potion if you plan to build heart generators as part of your arena. A Featherfall potion is NOT recommended, as the slower falling speed will make you more vulnerable to Fishron's charging attacks. Make sure to bring plenty of Greater Healing Potions from the biome mimics.

The Arena
Build a large box above ocean with which to fight Duke Fishron in; it should be at least 150-200 blocks tall and wide. It is not recommended to build up to space, as the slow fall effect will leave you more vulnerable to attacks. Using Pink Slime Blocks for the floor and ceiling will negate fall damage will allow you to free up an accessory slot as you will not require wings/horseshoes. Build side-walls on your arena to prevent falling out, and possibly leaving the Ocean as that will put Fishron into an enraged state. You will need a small opening from which to enter the arena and to fish from in order to summon him. Sunflowers, Campfires and Heart lanterns situated on the top and bottom of the arena will aid you with speed and regen. If you plan to build heart generators, it is recommended you build them on the outside edges of your arena. Otherwise, you could take too much damage if you land on or get stuck on them. They can also provide spots for Sharknados to land. Any heart generators built under your arena you will likely need a Heartreach potion to make use of.

As soon as you cast your line, move into the arena. As soon as you summon him, activate your buffs and reverse gravity. Then begin shooting in his general direction, your bullets will find their way to him. Each time you reach the top/bottom of your arena, reverse gravity so that you stay in a continuous fall. You will want to reverse sooner if you see that you may land on a tornado. Continue shooting and heal as often as possible. When he hits his second form, you will need to watch for the larger sharknados, as they will be able to form in air, but otherwise the strategy will not change. When he reaches his third form on expert, you will need to remember that he changes sides each time he reappears to charge at you; just keep shooting and you will kill the Duke.