How do I make the Demolitionist NPC happy in Terraria?

To make the Demolitionist NPC happy in Terraria, you need to understand the NPC happiness system, which was introduced in the 1.4 update. This system allows NPCs to have preferences for specific biomes and neighbors, which directly affects their happiness. A happy NPC will offer discounts on their items and, in some cases, sell unique items that are otherwise unavailable. The Demolitionist is a unique NPC who sells explosives and related items, making him valuable for mining and combat. To maximize his happiness, you need to place him in the right biome and pair him with the right neighbors.

The Demolitionist prefers the Underground or Cavern biomes. These biomes are located below the surface layer of the world, and you can identify them by the background walls and music. The Underground biome starts just below the surface, while the Cavern biome is deeper, usually below the Underground layer. To create a suitable home for the Demolitionist, you need to build a house in one of these biomes. The house should meet the basic requirements for NPC housing, which include walls, a chair, a table, a light source, and a door or other entrance. You can use any materials to build the house, but it must be in the correct biome.

The Demolitionist also has specific preferences for neighbors. He likes the Tavernkeep and the Mechanic, so placing him near these NPCs will increase his happiness. The Tavernkeep is an NPC who sells items related to the Old One's Army event, and the Mechanic sells wiring and mechanical items. Both of these NPCs can be found in the Underground or Cavern biomes, making it easier to create a happy environment for the Demolitionist. However, the Demolitionist dislikes the Nurse and the Arms Dealer, so avoid placing him near these NPCs. If he is too close to NPCs he dislikes, his happiness will decrease, and he will charge higher prices for his items.

To maximize the Demolitionist's happiness, you should also consider the density of NPCs in the area. If there are too many NPCs in a small area, their happiness will decrease. This is known as overcrowding, and it can negate the positive effects of placing the Demolitionist in the right biome with the right neighbors. To avoid overcrowding, try to space out your NPC houses and keep the number of NPCs in a single area to a minimum. A good rule of thumb is to have no more than three NPCs in a small area, but this can vary depending on the biome and the specific NPCs involved.

When building a house for the Demolitionist, you should also consider the layout of the biome. The Underground and Cavern biomes can be dangerous, with enemies like bats, skeletons, and slimes appearing frequently. To protect the Demolitionist and other NPCs, you should build a secure house with walls and a roof to prevent enemies from entering. You can also place traps and defenses around the house to keep enemies at bay. Additionally, you should ensure that the house is easily accessible for you, as you will need to visit the Demolitionist frequently to purchase explosives and other items.

One common mistake players make is placing the Demolitionist in the wrong biome or near NPCs he dislikes. This can significantly reduce his happiness and make his items more expensive. To avoid this, always check the biome and the nearby NPCs before placing the Demolitionist in a house. Another mistake is overcrowding, which can happen if you place too many NPCs in a small area. To prevent this, spread out your NPC houses and keep the number of NPCs in each area to a minimum.

Advanced techniques for maximizing the Demolitionist's happiness include using pylons to create a network of fast travel points. Pylons are special items that allow you to teleport between different biomes, and they can only be used if the NPCs in the area are happy. By placing the Demolitionist in the Underground or Cavern biome with the Tavernkeep or Mechanic, you can create a pylon in that biome, making it easier to travel between different areas of your world. This can save you time and resources, especially if you need to visit the Demolitionist frequently.

In terms of resource requirements, building a house for the Demolitionist is relatively simple. You will need basic building materials like wood, stone, and torches, which can be easily gathered from the surface and underground layers. If you want to create a more secure house, you may need additional materials like iron or lead for traps and defenses. You should also consider crafting a bed and setting your spawn point near the Demolitionist's house, as this will allow you to quickly return to the area if you die or need to restock on explosives.

Class and equipment considerations are not directly related to the Demolitionist's happiness, but they can affect your ability to gather resources and build a suitable house. If you are playing as a melee class, you may need to focus on defense and health to survive in the Underground or Cavern biome. If you are playing as a ranged or magic class, you may need to focus on dealing damage from a distance to avoid taking too much damage from enemies. Regardless of your class, you should always carry a pickaxe and a weapon when exploring the Underground or Cavern biome, as you will need to mine resources and defend yourself from enemies.

In summary, making the Demolitionist happy in Terraria involves placing him in the Underground or Cavern biome, pairing him with the Tavernkeep or Mechanic, and avoiding overcrowding. You should also build a secure house to protect him from enemies and ensure that the area is easily accessible. By following these steps, you can maximize the Demolitionist's happiness, reduce the prices of his items, and unlock unique items that are otherwise unavailable.