Guide:Skeletron strategies

Skeletron is a boss guarding the Dungeon, and killing him is necessary if you want to access the loot within. He's big, tough, hard to dodge, and can seriously ruin your evening many times over. Like any other daunting task in Terraria, defeating him is largely about smart preparation. The following are some hints, tips, and strategies to help you do so.

Weapon selection
When choosing one strategy over another, the biggest factor in your decision is likely to be weapon constraints. For Skeletron, ranged attacks are far more effective than melee attacks (with a few exceptions). The first time a player fights Skeletron they are unlikely to have many high-end pieces of melee equipment so ranged attacks are more often used. Remember, you're fighting the toughest enemy in the game, short of Hardmode and the Dungeon Guardian.

Ranged weapons
Skeletron's high defenses mean that most of the mid- to low-tier weapons aren't worth the time or money, so shurikens are pretty much out. Spiky Balls work great when spread around the Dungeon entrance, but they will disintegrate and can't be recovered once thrown.

The best way to go is combine high to moderate damage with a fast rate of fire:
 * If you wish to conserve ammo, the Flamarang and Thorn Chakram are both reasonably easy to get by this point.
 * Most pre-dungeon guns don't have enough damage-over-time to be useful, with the exceptions noted below. The Minishark is great, as is the Star Cannon, but both of these are expensive to use: the Star Cannon requires about 100 stars to do the job and the Minishark needs about 700 to 1,000 rounds of standard musket balls if you aim carefully (1250-1500 musket balls for the players with bad aim).
 * Using a Space Gun frees you from the constraints of ammo and deals decent damage, but you will need a lot of mana potions or Meteor armor to last the fight. Just hold down the left button for the whole fight, and predict where it is.
 * A bow and some decent arrows are comparatively much easier to get your hands on. A high-damage bow will be doing most of the work for you in such a case, so the difference between weak-but-cheap ammo and rare-but-high-damage ammo is a matter of personal preference. Either the Demon Bow or Molten Fury will do the job admirably.
 * The Demon Scythe is also an effective weapon in many fights, but requires a decent amount of mana and potions.

Melee weapons
The non-ranged and semi-ranged weapons have some use, but generally don't stack up to the ranged family.
 * Flails are excellent for damage and can consistently dish it out, but the only ones available at this point are the Ball 'O Hurt (at the low end of the damage scale) and the Harpoon. More on the Harpoon below.
 * The Fiery Greatsword does high-end damage and has excellent range for a melee weapon but is so slow to swing that most other weapons will outstrip it in the long run. The Phaseblade is also a fairly good weapon against him. Though if you happen to have a better weapon it could be done a bit easier.
 * The Thorn Chakram is relatively fast if you're within a close range, and can be launched almost as fast as the Harpoon. the Poisoned debuff is extremely useful during this fight, making the Thorn Chakram one of the better weapons to use in this instance.
 * Another Jungle weapon that is useful is the Blade of Grass to take out Skeletron's hands. If you use this weapon it is best to have a prefix like "agile"  or an accessory(s) that boost up it's speed.  However I don't recommend using the Blade of Grass to attack the head, instead use a ranged weapon.

Other
One slightly different approach is to use a tool with auto-swing, i.e. The Breaker or the War Axe of the Night, both of which are relatively easy to get materials for with lower-end gear. Neither has as much damage over time compared to the options above, but these weapons will keep swinging as the mouse button is held down, allowing you to concentrate on dodging. The Harpoon's auto-fire works incredibly well at point-blank range.

Dungeon weapons
Also to consider are these weapons not mentioned above: All of these weapons are as good or better than the other weapons in their respective categories but are found only in the dungeon, and thus cannot be obtained without either defeating Skeletron or trading with other players. A side option is to go in the dungeon at night and spawn Skeletron as his regular self, not his Dungeon Guardian self, then outrun him long enough to gather keys and open chests to find the good dungeon items.
 * Muramasa: Much like the War Axe and The Breaker, this sword has auto-swing and good damage output, not to mention a decent swing radius and speed. Just hold the button down and you're good to go.
 * Handgun and Phoenix Blaster: Easy to get ammo for and the Phoenix especially has stellar dps.
 * Blue Moon: An upgraded Ball 'O Hurt. Used the same way, and once Skeletron is down it's arguably easier to get than Sunfury.
 * Aqua Scepter: This weapon is best used with the Blue Moon or a ranged weapon, don't count on it to single handedly take down Skeletron. Blast away with the scepter then switch to something else while your mana recharges or just use potions.

Arena


The arena doesn't matter as much as it does in the other boss fights, but it can still be important. A large, flat surface with enough room to maneuver is key. Wood platforms may be used with decent effect, but keep in mind that they take time to drop through when dodging and too many platforms can interfere with attacks depending on the weapon/ammo used. A fairly straightforward and common practice is to simply flatten out the roof of the dungeon and fight Skeletron there. Keep in mind that the fight must occur at night, so you'll have to be comfortable dealing with Zombies and Demon Eyes (and possibly Eaters if you're near any corruption) or build a platform inaccessible to them. A ceiling is mostly unnecessary and tends to get in the way of many attacks.

Boomerang/Chakram users may prefer to fight Skeletron in the dungeon entryway to provide a ceiling for missed shots to return faster. Bow users can benefit from having a lot of open space to collect fallen arrows as they go. Melee users will want more platforms to aid mobility.

Armor
The more armor you have, the better. You should use the best armor available to you at the time, but if the best you have is Silver armor or lower then you should seriously consider holding off and continuing the fight later with better defenses. Shadow armor or better is highly preferred. And, as always, having more HP is a good thing. If your armor is far ahead of your weapons then you can sacrifice killing power in favor of survivability.

To boost your defense, keep in mind that accessories like the Obsidian Skull and Shackle are easy to obtain and will give an extra point of defense (or more, with random prefixes). Every point helps.

Ironskin Potions and Regeneration Potions will make the job easier for any player and are highly recommended. Two potions will last from sundown to dawn, provided the player stays alive the entire time.

Avoiding attacks


Skeletron attacks by either hitting you with his hands or spinning his head at you. Both attacks seem to come equally frequently unless one or both of the hands has already been killed.


 * The hands are difficult to dodge and will mostly come in from the sides. Both hands or one hand will attack at random, but just before this they will draw away from you in a kind of "wind-up" motion, then strike toward you and continue for a good distance onward. If you learn to read this attack it can be avoided more easily. Keep in mind that only the hands that will damage you; Skeletron's arms take up a lot of space and can be distracting, but they won't block your bullets or hurt you. Avoiding the attack is simply a matter of jumping at the right time: jumping too late won't give you enough time to dodge the hands and jumping too soon will let the hands adjust to your new position and hit you anyway. Wait and dodge the hands only after they've started their strike.
 * The head attack is much slower, but Skeletron's massive noggin does more damage and takes up a lot of space, especially when it's spinning. This makes the head somewhat difficult to dodge without the aid of Rocket Boots or another jumping aid, or platforms. The upside is that this is a great time for boomerang or harpoon users to rack up a ton of easy hits in a hurry, by staying just in front of the head and attacking like mad.
 * You can walk as fast as the spinning head (with a full set of shadow armor), so don't worry about speed when fighting the skull.

Potions and Equipment
1-2 Gravitation Potions (This enables you to move around in the air and avoid Skeletron easier)

Rocket Boots (Like the gravitation potions)

Hermes Boots (Makes it easier to avoid Skeletron)

General tips
(This may not be the case with single player as he disappears when you die.)
 * The hands are probably your biggest problems and have lower HP than the head, but it is not necessary to destroy them, since if the head dies the hands die with it.
 * The easiest way to last the fight is to go for the hands first: once they're gone, Skeletron will have nothing to do but spin his head at you and is much easier to dodge. Even killing just one hand makes the fight go much easier.
 * It's always preferable to summon Skeletron immediately after sundown since the fight must be finished in one night.
 * The lower your damage per second, the longer the fight will last. This also means that you're likely to need more potions and ammo.
 * If you are using a weapon with ammo, always have a backup sword or boomerang handy. The Zombies and Demon Eyes that you will encounter during the fight may not be worth wasting ammo on.
 * If your dungeon is a good hike away from your base and not easily accessible, build a small outpost nearby and save yourself the hassle of running all the way back. If it's close enough you can pick up the fight right where you left off and not have to start over each time.
 * You can also designate your spawn hut as the Nurse's home, wait for her to spawn in it and use her for pick-me-ups mid-battle.
 * If you specifically desire to use the Minishark for the Skeletron fight, defeating the Eye of Cthulhu or the Eater of Worlds a couple of times to sell the Demonite Ore and Shadow Scales is a great way to get the necessary gold.

Beating him again
Skeletron is much easier to beat once you've got access to dungeon equipment. Any of the hardmode-only gear makes the fight a cakewalk. If you must defeat him on a new world, all of the above strategies can still apply: It's simply easier the next time around.