What is the best way to defeat the Old One's Army event in Terraria?

The Old One's Army is a unique wave-based event in Terraria that requires careful preparation, strategy, and execution to defeat. This event is tied to the Tavernkeep NPC, who provides the Eternia Crystal Stand and Eternia Crystals needed to start the event. The goal is to defend the Eternia Crystal from waves of enemies, culminating in a battle against powerful bosses like Betsy in the later tiers. HereÔÇÖs a detailed guide to help you succeed.

First, letÔÇÖs discuss the mechanics of the event. The Old One's Army has three tiers, each corresponding to different stages of the game: pre-hardmode, post-mechanical bosses, and post-Golem. Each tier introduces stronger enemies and bosses, so your preparation must match the difficulty. The event takes place in a designated arena, and enemies will spawn from portals on either side of the map. Your job is to prevent them from reaching the Eternia Crystal in the center. If the crystal is destroyed, the event ends in failure.

To prepare for the event, youÔÇÖll need to build a proper arena. Start by placing the Eternia Crystal Stand in a flat, open area. Create a long platform with enough space to move around and fight. Add walls or barriers to funnel enemies into specific paths, making it easier to target them. Place traps like spiky balls or flame traps along these paths to deal passive damage. Additionally, set up heart lanterns, campfires, and honey pools for health regeneration. If youÔÇÖre in hardmode, consider using heart statues wired to timers for extra healing.

Next, gather the necessary resources and equipment. For pre-hardmode, focus on obtaining strong weapons and armor. A ranged or magic build works well, as you can attack from a distance. For post-mechanical bosses, upgrade to hardmode gear like the Megashark or Daedalus Stormbow. In the final tier, post-Golem gear such as the Terra Blade or Stardust Dragon staff is essential. DonÔÇÖt forget to stock up on potions like Ironskin, Regeneration, and Swiftness. Ammo and mana potions are also crucial if youÔÇÖre using ranged or magic weapons.

During the event, prioritize targeting enemies that pose the greatest threat. Flying enemies like Wyverns or Dark Mages can bypass your defenses, so focus on taking them down first. Use area-of-effect weapons like explosives or magic spells to deal with groups of enemies. If youÔÇÖre playing solo, consider using sentries from the Tavernkeep, such as the Ballista or Explosive Trap, to provide additional firepower. These sentries can be placed strategically to cover multiple paths.

One common mistake is neglecting to upgrade your sentries. The Tavernkeep sells tiered sentry summon items, and using the highest-tier sentry available for your progression is crucial. Another mistake is not managing your mana or ammo effectively. Always keep an eye on your resources and replenish them as needed. Additionally, avoid standing too close to the Eternia Crystal, as enemies will target you and potentially damage the crystal in the process.

Advanced techniques include using mobility accessories like the Shield of Cthulhu or Master Ninja Gear to dodge attacks and reposition quickly. If youÔÇÖre playing in multiplayer, coordinate with your team to cover different areas of the arena. For example, one player can focus on melee combat while another provides ranged support. This division of roles can make the event much more manageable.

In terms of class and equipment considerations, each class has its strengths. Melee builds are tanky and can deal high damage up close, but they may struggle with flying enemies. Ranged builds excel at taking out enemies from a distance, especially with weapons like the Chlorophyte Shotbow or Tsunami. Magic builds can unleash devastating spells like the Razorblade Typhoon, but they require careful mana management. Summoner builds can be effective with minions like the Stardust Dragon, but they rely heavily on sentries for additional damage.

Finally, letÔÇÖs look at specific examples. In the pre-hardmode tier, you might use a Molten Fury bow with Frostburn arrows to deal consistent damage. In the post-mechanical tier, the Daedalus Stormbow with Holy Arrows can clear waves quickly. In the final tier, the Terra Blade or Solar Eruption can handle both groups and bosses effectively. Always adapt your strategy based on the enemies youÔÇÖre facing and the resources you have available.

By following these steps and strategies, youÔÇÖll be well-prepared to tackle the Old One's Army event. Remember to stay mobile, manage your resources, and prioritize threats to ensure victory. Good luck!