How to Fix Unable to Connect to Friends in Slay the Spire 2 Multiplayer

One of the biggest surprises in Slay the Spire 2 is the addition of online co-op. Instead of climbing the Spire alone, players can now team up with friends and tackle runs together. Each player builds their own deck, but the group shares the same journey through the tower, making decisions about routes, battles, and rewards as a team.

Since the game relies on player synchronization, joining a friend's session requires a stable connection and proper matchmaking. While most sessions work smoothly, many players have encountered issues connecting to lobbies. If you've ever failed to join a friend's game, you're not alone.

Slay the Spire 2 Multiplayer Connection Issues

When you're unable to join a friend's lobby in Slay the Spire 2, you might experience any of these situations:

• The invite goes through, but you get stuck on a "connecting" screen indefinitely.
• A friend's lobby appears briefly, then instantly disconnects.
• You receive an invite but cannot join the session at all—the connection fails before the game starts.
• The game shows a generic connection error message without explaining the cause.

These issues are more frequent when players are in different regions or when the game's connection to platform servers becomes unstable.

Why You Can't Connect to Friends?

The problem usually stems from one of these three issues:

1. Unstable routing between players: The game needs to exchange data through servers or networking services. If the connection path between you and your friend is too long or passes through congested nodes, the handshake may fail.
2. Cross-region delays: Playing with friends in other countries often introduces longer, more complex connection paths. If any network node along the route is unstable, the attempt may time out.
3. Local network interference: Weak Wi-Fi signals, overloaded routers, or background downloads can interrupt the initial connection process, preventing a stable session from starting.

How to Fix Slay the Spire 2 Co-op Connection?

Use GearUP to Fix Connections

If you and your friends can't connect smoothly, it's likely that your routing node is malfunctioning, or—if you know some networking—you may find your NAT type is incorrect. However, we cannot manually intervene with nodes provided by ISPs, so you need GearUP's help.

GearUP is an AI-based online game network optimization tool that can accurately identify node status and construct the optimal path to connect to other players, ensuring low latency and no disconnections in Slay the Spire 2's connection mode, which can significantly improve the gaming experience.

GearUP

GearUP is very easy to use; it is designed to let players focus on enjoying the game without wasting time on complex network configurations:

1. Search for Slay the Spire 2, click the arrow or click "Boost" to start accelerating.
   
2. Keep GearUP running in the background — it will continuously provide network optimization, then launch the game.
   

※ For best results, both players should enable GearUP.

Try Restarting the Session

Sometimes the solution is surprisingly simple. If a friend cannot join your lobby, both players leaving the lobby and restarting the session can occasionally fix the issue.

Restarting the game client can also help. This refreshes the connection with the platform services and clears temporary networking errors that may have appeared during the previous session.

It might sound basic, but many players report that reconnecting both clients solves the issue more often than expected.

Check Your Local Network

Another thing worth checking is your own network environment. If you are playing on WiFi, interference or weak signal strength can interrupt the connection process. Moving closer to the router or switching to a wired connection can sometimes improve reliability.

It is also helpful to pause background downloads or streaming applications while playing. These activities can consume bandwidth and interfere with the game’s connection process.

Ensuring a stable and clean network environment makes it much easier for multiplayer sessions to start successfully.

Conclusion

Connection problems when trying to join friends in Slay the Spire 2 are usually related to unstable network routes or temporary platform connection issues. Restarting the session, checking your local network, and using GearUP to improve connection stability can all help resolve the problem. Once the connection works properly, co-op runs become much smoother and the focus can return to building decks and climbing the Spire together.