How do I make my netcode handle bad connections?

Design for flaky networks from the start: handle packet loss, latency, and drops gracefully, compensate for lag, ensure critical data is delivered reliably, and protect state against network failures. The biggest mistake is trusting the network to be reliable and low-latency like your local test setup, real players have high latency, packet loss, and dropped connections, so netcode built for a perfect network breaks for them. To handle bad connections: assume failures (handle packet loss, retries with backoff, timeouts, and drops gracefully so the game degrades rather than breaks), compensate for lag (prediction, interpolation, and lag compensation appropriate to your game), deliver critical data reliably (ensure important state and events arrive in order, reconciling, while using unreliable channels only for loss-tolerant data), and protect state (so a network failure during a save or transaction does not corrupt or lose progress). Test under simulated bad conditions (latency, packet loss). Bugnet captures the errors and crashes players hit under real network conditions, so you can see how your netcode fails on bad connections, fix those paths, and verify per version they stopped breaking under real conditions, ensuring your game stays usable for the many players on poor networks.

Why does my multiplayer break on some players' connections?

Because those players have worse network conditions, higher latency, packet loss, or unstable connections, than your test environment, and your netcode likely assumes a better network than they have. Multiplayer that works on your low-latency local setup can break for players on real-world connections (mobile networks, distant servers, congested links) with high latency, packet loss, and jitter. If your netcode trusts the network to be reliable and fast, it fails on these worse connections: lost critical data causes desyncs, high latency makes the game unresponsive or unfair, and drops cause errors or disconnects. The mistake is not designing and testing for the range of real connections players have. The fix is designing for flaky networks (handling loss, latency, and drops), compensating for lag, ensuring reliable delivery of critical data, and testing under realistic poor conditions. Bugnet captures the errors, desyncs, and crashes players hit under their real network conditions, so you can see how your multiplayer breaks on bad connections (which you may not reproduce on your good connection), fix those paths, and verify per version that it holds up under the real conditions players have, rather than only on a perfect network.

How do I test netcode for poor network conditions?

Simulate poor conditions (latency, packet loss, jitter, drops) in testing, and capture the errors players hit on real connections, since you cannot fully reproduce every real-world condition, field capture reveals the failures. The mistake is testing only on your good local connection, which does not surface how netcode fails on the bad connections real players have. To test for poor conditions: use network simulation tools to inject latency, packet loss, jitter, and disconnects during testing, so you can see how your netcode behaves under realistic adversity before release (does it handle loss, recover from drops, compensate for lag, stay in sync?). But you cannot reproduce every real-world condition, so also capture the errors and desyncs players hit on their real connections in the field, which reveals the failures your simulation missed. Bugnet captures the errors, desyncs, and crashes players hit under real network conditions, so the failures your testing did not cover are visible from real sessions, with the context to fix them, and you can verify per version that your netcode improvements held up under the real conditions players experience, combining simulated testing with field capture to make your netcode robust to poor connections.

Common Netcode Mistakes

Quick answer: The biggest netcode mistakes are trusting the network, no lag compensation, unreliable critical data, and not testing bad connections, fix these by designing for flaky networks and testing realistic conditions.

Netcode that assumes a perfect network breaks for real players on real connections. Here are the most common netcode mistakes and how to avoid them.

Trusting the Network to Be Reliable

The most common netcode mistake is assuming the network is reliable and low-latency, like your local test setup, when real players have high latency, packet loss, and dropped connections. Netcode built for a perfect network breaks on the flaky connections players actually have.

The fix is designing for flaky networks: handle packet loss, latency, and drops gracefully. Bugnet captures the errors and crashes players hit under real network conditions, so you can see how your netcode fails on bad connections and fix those paths, then verify per version they stopped breaking under real conditions.

Not Compensating for Lag

A second mistake is not compensating for latency, so the game feels unresponsive or unfair on anything but a perfect connection. Without lag compensation, prediction, or interpolation, real-world latency degrades the experience badly.

The fix is implementing appropriate lag handling, prediction, interpolation, and compensation, for your game type. Bugnet captures performance and errors under real network conditions, so you can see where latency degrades the experience and confirm per version that your lag handling improved it for players on real connections.

Sending Critical Data Unreliably

A third mistake is sending critical state or events over unreliable channels without ensuring delivery, so important updates get lost on lossy connections and clients diverge or break. Critical data needs reliable, ordered delivery, and treating it casually causes desyncs and bugs.

The fix is ensuring critical data is delivered reliably and in order (with reconciliation), while using unreliable channels only for data that can tolerate loss. Bugnet captures the desyncs and errors that result from lost critical data, so you can confirm the cause and verify your delivery fixes stopped the divergence in real sessions.

Avoid the big netcode mistakes: trusting the network, no lag compensation, unreliable critical data, and not testing bad connections. Design for flaky networks and test realistic conditions.