Guide:Duke Fishron strategies

"The mutant terror of the sea..."

Duke Fishron is a tough Hardmode Boss and one of the final Bosses in versions of Terraria. With very high movement speed, high damage and deadly sharknadoes, it can be considered one of the most difficult bosses in the game.

Spawn Condition
Duke Fishron can be spawned by using a with a  as Bait in the Ocean. Truffle worms can be found in the glowing mushroom biome.

It must then be fought within the Ocean Biome or else it will become enraged.

The Fight
Duke Fishron has two phases normally, and a third phase in and.

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

After each charge, he will execute one of the two Projectile attacks:
 * The first attack fires around 20 ;
 * The second attack will create two small Bubbles on either side of where he is located that will each generate a Sharknado. The Sharknadoes are not only tall and do damage, but they also fire towards the player.

Second Phase
When Duke Fishron falls below 50% 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 patterns 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 pop them all. It also makes it difficult to hit Duke Fishron consistently, so this can be a good time to refill your mana with a Mana Regeneration Potion or re-apply Ichor.
 * His Sharknado attack upgrades to summon a Cthulhunado. He will fire a special bubble that homes in towards the nearest player. The bubble deals no damage on contact, but it will spawn a Cthulhunado, an upgraded version of the Sharknado that is much taller, deals more damage, fires more Sharkrons, and lasts much longer.

Duke Fishron's charging attack is his primary attack and can be difficult to dodge when without proper mobility accessories.

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 move up or down. (The fastest way to drop down is to briefly mount a Slimy Saddle or Gelatinous Pillion). If he is right above or below you, then you need to quickly move left or right. Do not fly all the way into the space layer, or the reduced gravity will render you helpless.

One important element of the Sharknado attack 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.

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

Sharknadoes are quite tall; getting over them will require fast or an infinite flight mount like the.

The upgraded Sharknado attack is a bit more difficult to deal with. It's taller, 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 tornado 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. Do not allow the bubble to hit you while you are moving upwards straight or on the ground, or you are likely to take damage (and possibly get stunlocked) from it immediately.

Another important factor to note is that you should attempt to avoid a Cthulhunado by any means necessary. They deal about 100 damage, which will turn the fight in Duke Fishron's favor. Always use Wings to fly over them. Alternatively, use the Rod of Discord to teleport to the other side.

Expert Mode
Duke Fishron’s Phase 2 lunges are delayed by a second, requiring that you time your dodges a bit later than usual to avoid them.

When Duke Fishron drops below 9000 health, he will transform again and the background will notably darken, while making himself invisible except for his glowing eyes.

He will only be able to use his charge attacks in this stage, but he will gain the ability to teleport behind the player before attacking. The charges will come in a set pattern: After teleporting, he will successively charge once, then twice, and finally three times before the pattern resets.

While his contact damage is reduced, the high speed of his charges can cause you to get hit many times in a quick succession. Pay attention to his attack pattern, and make sure to not stand still during the fight. You should also try to get away from any Cthulhunadoes left from the second stage.

Because Duke Fishron is untargetable while teleporting, minions and many slower homing weapons will almost stop working entirely. As there won't be many opportunities to deal damage, you should try to deal as much burst damage as possible during his charges. Slow, highly-damaging weapons like the Sniper Rifle and Tactical Shotgun work well during this phase.

A possible strategy for this form is placing a teleporter with a pressure plate on top at surface level, and an actuated teleporter on a platform 200 blocks above, which you can use to fall endlessly, and giving Fishron a hard time hitting you.

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 in the Cthulhunado, so don't charge into it to collect his drops until it dissipates.

Terrain Preparation
The arena must be located in the Ocean, unless you're very confident that you can beat an enraged Fishron, which is usually not recommended.


 * Make an arena with 3 - 5 rows of Platforms, each about 50 tiles apart due to the height of the Cthulhunadoes. The arena should span at least the width of the Ocean. can be useful to outrun Duke Fishron's attacks, but since the player cannot travel through them, they can severely limit vertical movement and thus should only be used on the bottom row.
 * The arena must be very tall: the tornadoes are very tall, and require a significant amount of flight time to fly over.

Gearing up
It's highly recommended to defeat Golem first if you haven't already, as these tips will take that into account. For more information about this boss, check its own strategy guide.

By this point it's recommended to have 500 maximum health via the use of Life Fruits.

Armor

 * For melee users, the best offensive set consists of the, , and . Alternatively, can be worn if you prefer a hybrid set. If defense is preferred,  can be used with the.
 * For ranged users, the best offensive set consists of the /, , and or . The  and the  are viable, more accessible alternatives.
 * For magic users, the best offensive set consists of either or a hybrid set consisting of, , and .  can be used to heal when your health is running low.
 * For summoners, the best set consists of . For a bit more survivability, can be used.

Weapons
For Melee users:
 * The is a very powerful choice if you have defeated Martian Madness already.
 * The deals heavy damage, but can only be used safely when Fishron stays still, such as during phase transitions.
 * The is virtually just as powerful as the Influx Waver, and even stronger with high melee speed bonuses.
 * The is an excellent option due to its auto-targeting nature.
 * The has lacking DPS, but a very reliable homing projectile.
 * The can break through homing bubbles and Sharkrons while still dealing damage to Fishron, however, its range is lacking.
 * is the best Yo-yo that can be used at this point.
 * are very useful for stealing life combined with decent damage.
 * The is somewhat low in damage, but it makes up for this by homing in on Fishron during the fight.

For Ranged users:
 * The is an extremely powerful choice when used with Crystal Bullets, but will often be unable to target Duke Fishron when he is offscreen.
 * The is good for Duke Fishron's third phase as it can latch on to teleporting enemies. Try to fire on him right before he enters third phase.
 * The, , and are also highly effective when using Crystal Bullets. Chlorophyte Bullets are a more accurate but significantly weaker alternative.
 * The and  are weaker, but they are available much earlier in progression.
 * The is very useful with its extremely high  and splitting arrows, dealing damage to the Sharknadoes as well.
 * ,, or will reduce his defense significantly, since he is vulnerable to Ichor.
 * The is powerful against him, if you have defeated the Frost Moon.  is noticeably stronger, but lacks homing abilities.
 * The with Ichor or Holy Arrows can perform excellently against him.
 * The is very effective.

For Magic users:
 * The is very strong due to its excellent DPS, although it requires you to get closer than with other weapons.
 * The is also very strong because of its homing ability and high DPS.
 * The spell is helpful as it reduces his defense and easily pops all the Detonating Bubbles.
 * is a higher DPS alternative to the Golden Shower that also lowers his defense more, at the cost of having to get a bit closer.
 * The is effective due to its homing nature allowing one to focus on dodging, especially during the third and final phase in Expert/Master Mode.
 * The clears out bubbles easily and deals moderate amounts of damage.
 * The is very good for attacking while he is stationary.
 * The can be used if the player has already defeated Martian Madness.
 * The can deal a lot of damage and only needs to be cast once in a while.
 * The is also a viable option.
 * The, , , and are the best pre-Plantera magic weapons against this boss.

For Summoners:
 * The is the best minion weapon available. It should be used with a combination of, for stacking tag damage.
 * The is also reliable and tends to completely nullify Fishron's bubbles, but depends heavily on tag damage from whips. It should be used with  and.
 * The provides the highest tag damage in the game, but it is only available after Empress of Light has been defeated. It can replace Morning Star on the above setups.
 * The is a powerful alternative after its AI buff in 1.4.1.2. It should be used with, though you should be mindful of its slightly shorter range.
 * If none of the above weapons are available, the performs better than all other options due to its flawless accuracy and ability to pop Detonating Bubbles. It should be used with  and.

Accessories

 * are a must-have for the fight. The can make them significantly faster, making it easier to get over the Cthulhunadoes and dodging his attacks while flying.
 * Alternatively, one can obtain the . The high vertical speed makes it an ideal choice for dodging Duke Fishron without the need of the Frog Leg, though having the Frog Leg can make it even more effective at dodging Cthulhunadoes. Desktop users can also use the.
 * The allow for increased ascent speed with wings and fast running, even on normal tiles. On,  or  can still give the increased movement speed.
 * The and  provide a dash, which is invaluable for mobility.
 * Accessories that increase damage are a must have for ending the battle sooner. The best choices include the or, , , and.
 * or can prevent heavy damage from getting trapped inside a Sharknado or a big group of homing bubbles.
 * Due to the boss' high damage, the or  can almost completely restore the player's Mana from one hit.
 * If you are using or another yoyo, use a.
 * will both allow for increased regen and reduced time for the debuff. The Philosopher's Stone effect can be used without the need of investing an accessory slot by keeping it on a vanity slot until needing to heal.
 * The mount is a good replacement for Wings. While its movement is generally slower and less versatile due to being unaffected by other mobility accessories, it can save the slots for other defense or damage improvements.
 * An will protect from the  debuff and those caused by, and will also provide knockback resistance.
 * The mount can be used in this fight due to its high mobility through water without having to use asphalt blocks.
 * and could help you to move fast vertically, which could be extremely useful during the 3rd phase.

Potions and Buffs

 * is highly recommended as it will destroy the Detonating Bubbles Fishron spawns before they reach the player.
 * and, and  will improve survivability.
 * Any food item that can provide the buff is very welcome.
 * can help you evade Duke Fishron's attacks.
 * and/or for a boost in damage output.
 * and potions are a must for Magic users.
 * can be used as a substitute for a platform in the Ocean.
 * can free up an accessory slot. It is recommended to use with them.
 * Melee characters should use the debuff and the  if available.
 * If you are facing him at night, a, , and will improve visibility.
 * increases the damage output for all classes.

Minecart Strategy
This strategy differs from others in that it doesn't use a 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 the arena.

Materials

 * 600-1200 normal minecart tracks for building loop + 2 booster tracks
 * Any kind of hammer

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.

It should be noted also that arena shouldn't exceed Ocean biome.

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 can easily outrun him causing Fishron to despawn, which is 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.

Abuse of Invincibility Frames
Standing in Lava with an Obsidian Rose and a Cross Necklace equipped will give the player invincibility frames for almost all of the fight while taking extremely little damage from the Lava due to the Rose's effects. this can also be done standing on a Spike.

Enraged Anti-Gravity Hook Strategy
When Enraged, Duke Fishron is much faster and does much more damage. But with this strategy, this strength can be turned into a weakness. What you must do is get an Anti-Gravity Hook and place one or more platforms in the air. After Duke Fishron becomes enraged, you use your Anti-Gravity Hook in the platform and start using it to spin in a circle. This makes it possible to dodge all attacks. Keep in mind that this strategy only works with enraged Duke Fishron, because in his enraged behavior he will do nothing but attempt to ram you. Then you use the hook on the platform, start spinning and dodge his charges.

The Black Spot (outdated as of 1.4.1)
In Master Mode, it is possible to defeat Duke Fishron with, as the mount is faster than the Duke. It only requires flying back and forth across the ocean, attacking the Duke.

Things to keep in mind:


 * All the general tips for items (potions, reforges, etc)
 * Arena (campfire, star in a bottle, heart lantern, etc)
 * Be careful to not to go too far out of the ocean

Additional tips:


 * Since you already have ability to fly, you no longer have the need for boots or wings, meaning you have two extra accessory slots. Good candidates for replacement are:
 * or
 * or
 * for players with a Crimson world
 * or any class-specific counterparts
 * or for melee users
 * It is recommended to use for this fight, as the Sharkrons will occasionally hit you as you pass by.
 * A or its upgrades are also recommended, so you can negate the knockback taken from a stray Sharkron.
 * You will also need a dashing accessory for the final stage, like a or.
 * Duke has a lot of defense, so use Ichor to lower it. The Duke is not immune to Cursed Flames, either, so use that to your advantage.
 * For the final stage, switch one of your accessories to a so you don't take fall damage when falling to the bottom platform. Using autopause will make it easier to open your inventory.

The fight itself is pretty simple, just make sure to watch out for the Sharkrons.

The only dangerous thing is the last stage (on Expert or Master):


 * 1) Before the fight, set up an arena high up in the air that spans across the ocean. When the Duke is transforming into his third stage, quickly make your way up to the platform.
 * 2) When the Duke teleports behind you, fall off the platform and start dashing away from his line of charge. Repeat this process until you reach your bottom platform. You will no longer need the ship mount for this.
 * 3) When you reach the bottom platform, use a  and repeat step two. When you reach the top platform, rinse and repeat.