Multiplayer Game Development
Networking architecture and synchronization principles.
1. Architecture Selection
Decision Tree
What type of multiplayer?
│
├── Competitive / Real-time
│ └── Dedicated Server (authoritative)
│
├── Cooperative / Casual
│ └── Host-based (one player is server)
│
├── Turn-based
│ └── Client-server (simple)
│
└── Massive (MMO)
└── Distributed serversComparison
| Architecture | Latency | Cost | Security | |--------------|---------|------|----------| | Dedicated | Low | High | Strong | | P2P | Variable | Low | Weak | | Host-based | Medium | Low | Medium |
2. Synchronization Principles
State vs Input
| Approach | Sync What | Best For | |----------|-----------|----------| | State Sync | Game state | Simple, few objects | | Input Sync | Player inputs | Action games | | Hybrid | Both | Most games |
Lag Compensation
| Technique | Purpose | |-----------|---------| | Prediction | Client predicts server | | Interpolation | Smooth remote players | | Reconciliation | Fix mispredictions | | Lag compensation | Rewind for hit detection |
3. Network Optimization
Bandwidth Reduction
| Technique | Savings | |-----------|---------| | Delta compression | Send only changes | | Quantization | Reduce precision | | Priority | Important data first | | Area of interest | Only nearby entities |
Update Rates
| Type | Rate | |------|------| | Position | 20-60 Hz | | Health | On change | | Inventory | On change | | Chat | On send |
4. Security Principles
Server Authority
Client: "I hit the enemy"
Server: Validate → did projectile actually hit?
→ was player in valid state?
→ was timing possible?Anti-Cheat
| Cheat | Prevention | |-------|------------| | Speed hack | Server validates movement | | Aimbot | Server validates sight line | | Item dupe | Server owns inventory | | Wall hack | Don't send hidden data |
5. Matchmaking
Considerations
| Factor | Impact | |--------|--------| | Skill | Fair matches | | Latency | Playable connection | | Wait time | Player patience | | Party size | Group play |
6. Anti-Patterns
| ❌ Don't | ✅ Do | |----------|-------| | Trust the client | Server is authority | | Send everything | Send only necessary | | Ignore latency | Design for 100-200ms | | Sync exact positions | Interpolate/predict |
Remember: Never trust the client. The server is the source of truth.
When to Use
This skill is applicable to execute the workflow or actions described in the overview.
Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.