How should I prepare for Hardmode?
3 things happen when you go to hard more:
- stronger enemies and bosses appear.
- Corruption/crimson spreads quicker
- Hallow biomes appear and spread.
To prep for stronger enemies/bosses, you should make sure you have top tier pre-hardmode weapons/armor/accessories and 400 max health. ie: Molten armor and a strong weapon like nights edge.
Getting a surface mushroom biome with a house for the Truffle NPC and then buying a mushroom spear as soon as he moves in after hardmode will make surviving much easier. The spear has decent knockback, good damage, and can hit enemies through walls.
You should get a Molten pickaxe to make Colbalt/Pallidium mining possible early on. quickly breaking Demon Alters and raising yourself to at least oricalcum armor quickly will make the common enemies much more bearable.
If you care about the lose of your natural biomes then the spread of corruption/hallow is a problem. You cannot control where it spawns but you can harvest the biomes blocks and create artificial biomes later on. However, I think waiting until you can get the Steampunker NPC and can buy the Clentaminator to remove hallow/corruption is a better use of time.
Steps to prepare for hard-mode. Note, all of these are actually optional, but the more you actually get done before going to hard-mode, the easier you will have it when in hard-mode.
- Build a full Molten Set. Tools, Weapons, Armor. You need the molten pick-axe to mine the new ore you will be seeing in hard-mode.
- All that weird equipment you have been hoarding that are also "Materials" - get them sorted. You will be able to combine these pretty early.
- Quarantine your Corruption / Crimson sites by digging a 4-block wide trench around the entire thing. Line the top or bottom with a non-corruptible material like Wood. This will help you preserve important biomes like the Desert and the Jungle.
- Get your home base super secured. Elevate it, and break it into manageable sections.
- Build a sky bridge.
- Build a dedicated battle arena for bosses.