What are the minimum room size requirements for NPC housing in Terraria?

In Terraria, NPC housing is a crucial aspect of the game, as it allows you to attract and house various NPCs who provide essential services, such as selling items, crafting materials, or offering buffs. To ensure an NPC can move into a house, the room must meet specific size and content requirements. Understanding these requirements is key to building functional and efficient bases.

The minimum room size for NPC housing in Terraria is 60 tiles in total, with a maximum of 750 tiles. This includes both the floor and ceiling space. The room must be at least 6 tiles wide and 10 tiles tall, but these dimensions can vary as long as the total tile count falls within the 60-750 range. The room must also have a solid block floor, walls (either natural or player-placed), a light source, a flat surface item (like a table or workbench), and a comfort item (like a chair or bed). Additionally, the room must be fully enclosed, with no gaps in the walls, and it must have a valid entrance, such as a door or platform.

To build a valid NPC house, start by selecting a location. Flat terrain is easiest to work with, but you can also build on uneven ground by leveling it with blocks. Use any type of block for the floor, walls, and ceiling, but ensure the walls are fully enclosed. Place a door or platform for entry, and add a light source, such as a torch or lantern. Next, place a flat surface item, like a table or workbench, and a comfort item, like a chair or bed. Once these elements are in place, the room should be valid for an NPC to move in.

One common mistake is forgetting to fully enclose the room. Even a single missing wall tile can invalidate the house. Another mistake is using platforms as the floor without adding a solid block somewhere in the room. Platforms alone do not count as a valid floor for NPC housing. Additionally, ensure the room is not too close to corruption, crimson, or hallow biomes, as these can prevent NPCs from moving in.

Advanced techniques include optimizing space by stacking multiple rooms vertically or horizontally. For example, you can create a multi-story building with each floor housing a different NPC. Use platforms as stairs between floors to save space. You can also theme your houses using specific blocks and furniture to match the NPC's personality or the biome they are in. For example, the Dryad might appreciate a house made of living wood in a forest biome.

Resource requirements for building NPC houses are minimal. Basic materials like wood, stone, and torches are sufficient for starter homes. As you progress, you can upgrade to more durable or decorative materials, such as bricks, glass, or gemspark blocks. Preparation involves gathering these materials early in the game, as NPCs like the Guide and Merchant can move in quickly after meeting their spawn conditions.

Class and equipment considerations are minimal for building NPC houses, as no specific tools or abilities are required. However, having a pickaxe or axe can speed up the process of gathering and placing blocks. If you are building in dangerous areas, consider equipping armor or weapons to defend against enemies.

A specific example of NPC housing is creating a compact apartment complex. Start by building a 6x10 room with wood blocks and walls. Add a door, a torch, a table, and a chair. Repeat this design vertically, stacking rooms on top of each other with platforms as stairs. This setup can house multiple NPCs in a small area, making it ideal for early-game bases or limited space.

In summary, NPC housing in Terraria requires careful attention to room size, walls, lighting, and furniture. By following the guidelines and avoiding common mistakes, you can create functional and aesthetically pleasing homes for your NPCs. Advanced techniques like space optimization and thematic designs can further enhance your base, making it both practical and visually appealing.