How to Install Core Keeper and Join a Server

You wake up underground in a circle of light about four tiles wide. Outside that circle is black — not dark, not shadowed, black — and the game has just told you that the ancient core in front of you needs powering and said nothing whatsoever about how. Your first hour is spent mining a corridor into nothing while placing torches behind you, because the moment you stop placing torches you cannot see the wall you are digging.

Core Keeper understands something most survival games forget. Darkness is only frightening when it stops you doing things, and here it stops you doing everything.

It is a top-down mining and survival game for up to eight players, built by a small studio, and it spent a long stretch in early access before its full release. Listings for it collect on the game's hub.

What you need

• A Steam account
• Core Keeper, which is a paid game
• Very little disk space — this is a pixel-art game and it is small by modern standards
• Almost nothing from your hardware

That last point matters more than it sounds. This is a game that runs comfortably on a laptop that struggles with everything else you own, which makes it one of the better options when the group you play with does not all have the same machines.Our Steam guide deals with signing up, if you have managed to avoid it until now.

The loop, and why it holds people

You mine. You find ore. The ore makes better tools, which mine faster and reach materials the previous tier could not touch. Each tier of ore wants a new workbench, and each new workbench opens a set of recipes that assumes you have the tier before it.

Stated like that it sounds like every crafting game ever made. Two things make it different in practice.

The map is not generated in front of you, it is excavated. There is no terrain to walk across. Everything is solid rock until somebody removes it, so the shape of your world is a record of where people have been. A base built by four players after twenty hours looks nothing like one built by a solo player, because the corridors go to different places for different reasons.

Progress is gated by bosses rather than by time. The core wants power, and power comes from defeating specific creatures scattered through the biomes. Until you do, the door to the next part of the game stays shut. This gives a co-operative session an obvious shared goal, which is exactly what most sandbox games fail to provide and why groups drift away from them after a week.

The first three

The early bosses are the ones everybody remembers, and they teach three different lessons.

Glurch the Abominous Mass sits in a slime-covered arena and bounces. The fight is about the arena as much as the creature — there is not much room, the floor works against you, and the answer is usually to make more room before you start.

Ghorm the Devourer does not sit anywhere. It travels a fixed circular route around the world, chewing a permanent ring through the rock as it goes, and you will find that ring long before you find the thing that made it. Finding a tunnel with no maker in it and realising that the maker is coming back around is one of the better moments the game has.

The Hive Mother is a stationary fight in the clay layer and it is the first one that will kill an underprepared group. It is also the point where people stop treating food and equipment as optional.

Past those the world opens into further biomes with their own titans, their own hazards and their own materials. The structure holds throughout: find the thing, kill the thing, the core takes another step.

Cooking, farming and the parts people skip

The survival systems here are gentler than the genre standard and they are not decoration.

Food gives you buffs rather than merely keeping a meter from emptying, and cooking two ingredients together produces a dish with both effects. Working out which two things to combine before a boss fight is real preparation rather than busywork, and a group that farms properly walks into fights with advantages a solo player is missing.

Farming works underground because you make it work — seeds, tilled ground, watering, and light. Growing things in a cave is a small engineering problem and it is one of the more satisfying builds in the game.

Fishing exists and is worth more than it looks. Several useful ingredients only come out of water.

Playing together

Here is the part that matters for a site about servers, because Core Keeper offers more than one route and they are not equivalent.

Playing on somebody's machine

The simplest option is that one person hosts from inside their game. Their world, their save, and the game generates an identifier they can pass to everybody else. It is a long string, it goes over Discord, and the other players paste it in.

This works well and it needs no configuration whatsoever. No router settings, no rented box, nothing.

It has one limitation, and it is the limitation every hosted-from-the-game setup has: the world only exists while the host has the game open. If the host goes to bed, the world goes with them. If the host loses interest in the game two weeks in, everybody else's progress is on that person's hard drive.

For four friends playing on the same evenings, that is fine. For a group that wants to log in at different times, it is the thing that eventually kills the world.

Running a dedicated server

The alternative is a machine that runs the world without anyone playing on it. Core Keeper supports this properly — a dedicated server is distributed separately from the game itself rather than being something you improvise.

The advantages are the usual ones and they are decisive for a group of any size. The world is always there. People play when they can rather than when the host can. Nobody's holiday pauses the base. And the save lives somewhere neutral rather than in one person's user folder.

The cost is that somebody has to run it, on a machine that stays on, and either that is a spare computer at home or it is rented. What game server hosting actually costs covers the money side honestly, and where to host it covers picking a region — less critical for a game at this pace than for a shooter, but still worth getting roughly right.

How many slots to buy is the other question worth answering before you pay for anything, and the answer for this game is usually a smaller number than people first choose.

Joining a listed server

Where a public server exists, joining it uses an address rather than a shared code, and the same rule applies here as everywhere else on this site: copy the port with the IP. A host running several worlds on one machine has moved most of them off the default, and an address without its port fails in a way that looks exactly like the server being offline.

Public listings for Core Keeper collect on the hub. The scene here is smaller than in the big survival games, and most play happens in private groups rather than on open servers — which is worth saying plainly rather than implying a bustling public population that is not there.

What eight players actually changes

The player cap is generous and the game scales oddly with it, in ways that are worth planning around.

Combat gets easier. Bosses that are genuinely difficult for one person become manageable with four, because the arena problems that make them hard are problems of attention rather than of raw numbers.

Everything else gets harder to coordinate. Eight people mining in eight directions produces a base with eight entrances nobody agreed on, and a storage situation that will make somebody upset. Groups that do well pick a direction and a storage convention early, and it is the least exciting advice in this guide and the most useful.

The natural group size is three or four. Enough that boss fights work and somebody is always doing the thing you find tedious, small enough that the base stays coherent.

Problems you will actually hit

You cannot see anything. Working as designed. Torches are cheap, place them constantly, and treat running out of them as the emergency it is.

Everything one-shots you in a new biome. You have gone deeper than your equipment. Core Keeper does not put a wall in front of you when you are underlevelled — it lets you walk in and find out. Go back, mine the tier you skipped, return.

The world is on somebody else's computer and they are not online. The known failure of hosting from inside the game. Move to a dedicated server before this becomes a problem rather than after.

A friend cannot connect with the code. Codes are long and get mangled by chat clients that helpfully format them. Send it as plain text, and check for a missing character at either end.

You lost your base. The map is enormous and identical in the dark. Place markers, build recognisable landmarks at junctions, and dig your main corridors in straight lines from the core.

If this is your kind of game

The obvious neighbour is Terraria, which shares the dig-and-craft-and-fight-a-boss structure in two dimensions and has a much larger server scene. Starbound takes the same idea across planets.

Necesse is the closest relative in perspective and pace — top-down, co-operative, built around settlements — and is the recommendation if what you liked here was the overhead view rather than the caves specifically.

For the same co-operative progression at a slower pace and in three dimensions, Valheim and Vintage Story both run on dedicated servers that a group keeps alive for months, and both have the same shape of problem: somebody has to host it, and the group that solves that early is the group still playing at Christmas.

If it is the building and the logistics that caught you rather than the fighting, Factorio is where that instinct goes to become a full-time occupation.

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JoinGG is a live directory of community game servers. Every listing is queried directly every fifteen minutes, so the player count you see was measured rather than reported by its owner, and each one carries a copyable connect address. Core Keeper servers are listed here, and every game on the site has its own hub. Player counts across every game are on the statistics page.