Guide:Expert Mode

Summary
"Fortune and Glory, kid" Expert Mode is pretty much a harder mode of the game. It offers harder enemies, slightly increased effects of debuffs, and unique boss loot. It is recommended to play the normal gamemode of the game before playing this gamemode because it is far more difficult.

The Beginning
Possibly you already know the basics (Get wood, break pots, and grab surface chests). It is pretty useful to use a ranged character for the beginning of the game since the enemies are far stronger and does a lot of damage when they touch you. Don't go exploring at night when you still have beginner gear because the zombies will be swarming you and kill you instantly.

Dig a hole straight down next to your base, (and dont forget to make a way up and a way down as well) until you find a large cave. Find minerals until you get stronger armor and weapons. And be sure to grab any chests you find.

Preparing for the Bosses
Bosses are harder in expert mode because they have 2x health and 2x damage, they have a third stage when normally they only have one, so be prepared.

At this point you would've had a few Heart Crystals and have 180 health, if you find another Heart Crystal don't consume it because if you do, it will trigger the 1 in 3 chance of spawning the Eye of Cthulhu while unprepared, so keep that one until you have gear like these:
 * Gold or Platinum Armor
 * Musket or The Undertaker
 * Ice Blade or with some luck, Enchanted sword
 * Cloud in a bottle (Blizzard of Sandstorm if you can)
 * Hermes boots or its counterparts
 * A very well-made arena will give you more chances to win
 * Minecarts are very cheap against EoC, as you can then travel faster than the eye himself

Eater of Worlds
Eater of Worlds is a much harder boss in expert mode than in normal mode, but he also drops a very useful accessory, known as the Worm Scarf. The segments shoot vile spits, he travels/digs at a much steeper rate so it'll be harder to dodge in the underground, and overall boosted damage and health. Here's a few tips:
 * A simple weapon of choice would be at least a Gold/Platinum Bow with Jester's Arrows. This has great pierce.
 * Avoid using yoyos, they're great in general but not against worms like this.
 * Inferno potion would help against the vile spits but assuming you're not in Hardmode, you can only get this from shadow chests, this is completely optional.
 * Waterbolt is a terrific magic weapon.
 * Aqua Scepter is great too.
 * Spiky Balls can be bought from the tinkerer and they're still great in expert mode!

Brain of Cthulu
Brain of Cthulu has a few differences, including chances for debuffs, so make sure you dodge as much as you can. In the first phase, the servants are twice as aggressive. In the second/last phase, he spawns decoys to try and confuse the player, the lower the health, the more transparent the decoys are. Here's a few tips:
 * Spiky Balls exploit the entire nature of this boss, the #1 weapon of choice

Skeletron
Skeletron is one of the hardest bosses you'll ever fight in expert mode, the heads health is nearly doubled, the hands health are nearly tripled, you have to defeat the hands before attacking the head, and once they're removed he shoots skulls that hurt half the damage from his head. What's more, here's a few tips:
 * Shield of Cthulu, obtained after defeating Eye of Cthulu, is a very useful accessory for mobility.
 * Try building an arena that is both good for vertical and horizontal movements. It's easy to make the mistake of making a straight row of platforms, so make sure you have a tall arena as well.
 * If you want to challenge yourself and fight Skeletron before EoC, use a hook with minecart tracks to hook to. With a nice hook, Sapphire or better, the boots aren't even mandatory. However, it his highly suggested that you at least use the accessories as said above for EoC.
 * Spinning head must be avoided, it can leave you trapped and it's game over.
 * In the second phase, if you get used to the tempo of the skulls, you can cut through every few of them at the right time.
 * If fighting him for the first time, try moving around in a circle when he starts shooting the skulls.
 * If you fight the Queen Bee before and obtain the Bee's Knees, it will make killing Skeletron nearly three times as fast. Drink an Archery potion and he will be a piece of cake.

Queen Bee
Queen Bee only has differences when it comes to speed an buffed stats. Still however, it's important you exploit her nature, in different ways.
 * The stingers still can't pass through blocks.
 * She can still only shoot downwards.
 * The lower the health, the faster she shoots the stingers.
 * The lower the health, the faster she dashes.
 * The lower the health, the more bees she'll spawn at a faster rate.
 * The lower the health... Yeah, harder.

Duke Fishron
(This page is still incomplete and is been working on)
 * For Duke Fishron, you can exploit his third form by jumping at a steady tempo, it may take a few tries but if you have a bottle equipped and you just jump up and down, falling/jumping RIGHT as he teleports each time, you'll be off the hook.

General Tips
Expert mode doesn't just make you prepare more, it makes you more cautious with getting hit. You can actually get so good at dodging that a Worm Scarf or Band of Regeneration won't be needed at all. Here's a few tips:
 * Blizzard in a Bottle (or even Sandstorm) instead of Cloud in a Bottle make a tremendous difference in the long run.
 * Sandstorm in a Bottle will give you the opportunity for the Bundle of Balloons without even traveling in another world, an extremely useful accessory. Just get the other two bottles, and then fish up in the sky for the Sky Crates and get two Shiny Red Balloon's, the third can be gotten from a floating island originally in your world.
 * The tips above include bottles because these accessories are essential for dodging, vertically. If you were fighting Duke Fishron, and he dashes towards you, if you were just wearing wings, you'd most likely get hit. But if you had the bundle equipped, he would be a piece of cake.
 * If you don't know what accessories to replace with these bottles, replace the Cobalt/Obsidian Shield or any other type of accessory that neglects knockback. This is a possibility because dodging is much more important, and if you never get hit, you'd never need the shield. Besides, the shield helps getting hit less annoying, while the bottle's and balloon's helps getting hit less often. Easy to say which method is more useful.
 * Yoyos are a great addition to the game, and the name is shouted in expert mode. Amazon and Yelets are some of the cheapest ones to get. Amazon can be crafted for little materials right in the beginning of the game in the jungle. Amarok can be gotten from any enemy by chance in the Ice biome in Hardmode. Yelets can be gotten from any enemy by chance in the Jungle biome after at least one mechanical boss is defeated in Hardmode.