Guide:Enemy farming

Monster farming is an essential part of Terraria. Some items have a very low drop rate; the way to get around this problem is to build a system that will consistently kill monsters until the desired item is obtained.

Monster farming basics
The most essential part to monster farming is knowing the basics of NPC spawning. Monsters will always spawn off screen, their spawn rate is not always the same, and there is a limit to how many monsters can spawn in an area at one time.