Minimap

The minimap is a live picture of the terrain around you, and it remembers. A tile you have seen stays drawn at the brightest you ever saw it, even after you leave and the area falls back into darkness.

The catch is in the word seen. Walking a cave with no light source maps nothing at all. You can cross half a world in the dark and come back to a blank strip where you know you have been. Carry torches or a light pet if you care about the map filling in and not only about surviving the trip.

How quickly tiles get logged depends on your video quality setting, and how wide the logging area is depends on your zoom. Zoomed in, a smaller ring around you gets recorded per second. If you are exploring specifically to fill in the map, zoom out. None of it is frozen once drawn either: a meteor landing or hardmode biome spread rewrites the affected area the next time you are nearby.

• Portrait. The small framed square in the corner, with zoom controls on the frame itself. The equals button is the only way back to default scale, since no key is bound to it.
• Overlay. The whole screen becomes a transparent map with icons still drawn over the world. This is the mode worth learning.
• Full screen. An opaque map you pan with the mouse or the arrow keys while your character stays put, with a background that changes to match the biome you are standing in. Autopause does not hold here: opening it unpauses the game.
• Hidden. Off entirely. Areas still map while it is hidden, so turning it off for screen space costs you nothing.

Players, town NPCs and bosses appear as head icons, and hovering one names it. That makes the map the fastest way to find an NPC who has wandered off, and the fastest way to work out where a boss went when it has flown clear of the screen.

Two NPCs are absent on purpose, and both are the ones who never move in: the Skeleton Merchant and the Old Man. Enemies do not appear at all, so the map will never warn you about what is waiting in the dark ahead of you.

In PvP, icons only render for players on your own team. Everybody else is invisible to you and you are invisible to them.

Double clicking anywhere on the map drops a marker there for fifteen seconds, visible to everyone currently looking at their map. It does nothing mechanically, there is no cooldown, and you can stack as many as you like.

In multiplayer that is your pointing finger. Mark the entrance you want the group at instead of describing it in chat. Alone it is a fifteen second memory aid, which is long enough to note where you abandoned a shaft while you deal with whatever interrupted you.

Map data is saved with the character, not with the world. Bring a fresh character into a world you have fully explored and they start blank. Bring an explored character into someone else's copy of the same world and they keep everything they knew.

The files sit beside your player data, one per world, named after the world's internal identifier. That matters for exactly one reason: moving a character into Steam Cloud can lose them, and there is no way to recover a map short of walking it all again.

• Zoom overlay mode all the way in and it renders at roughly the same scale as the world itself. In a dark cave with no light source that is a working substitute for vision, since terrain you have already mapped stays lit. It shows no enemies, so it gets you through a corridor rather than through a fight.
• Zoom the other way during a boss fight and you can track something circling far outside the screen edge. Pushed far enough out, the whole world fits at once, which is how you find a jungle or a dungeon you have not visited.
• Paint registers on the map. A few hundred blocks of a distinctive color makes a landmark readable at any zoom, which is the cheapest signposting in the game and the only kind that survives being covered over.
• During a thunderstorm the map background darkens and flickers along with the lightning outside. Purely cosmetic, but a decent tell that the weather has turned while you were underground.