Multiplayer Fundamentals

Why is lag frustrating in some online games but barely noticeable in others? Why does matchmaking sometimes create stomps? Multiplayer design is not just 'connect players', but a system of decisions about latency, fairness, and trust.

• **Clash of Clans** - async attacks. Attack when you want, defender isn't even online. Perfect for casual mobile
• **Fighting games rollback** - Killer Instinct's netcode revolution. Same latency feels way better with prediction
• **Valorant's anti-cheat** - Vanguard runs at kernel level. Controversial but effective. Design + tech approach

Synchronous vs Asynchronous

**Synchronous multiplayer** - all players online simultaneously, interacting in real time. **Asynchronous** - players take turns, not necessarily together. Different design, technology, and player commitment requirements.

**Mobile games and async.** Clash of Clans attacks = async. You attack a base whenever you want, the defender isn't even online. Perfect for mobile - no commitment to a specific time.

**Choosing model:** - Target audience availability (casual = async) - Core gameplay requirements (twitch = sync) - Technical resources (servers cost) - Social goals (strong bonds = sync)

Designing for Latency

**Latency (ping)** - delay between action and server response. 20ms = excellent, 100ms = noticeable, 200ms+ = frustrating. Game designers must design AROUND latency, not ignore it.

**Rollback netcode revolution.** Fighting games switched from delay-based (wait for opponent input) to rollback (predict, correct if wrong). Same latency feels 3x better. Killer Instinct → industry standard.

**Design for latency:** - Test at high ping (simulate 200ms) - Slower gameplay = more forgiving - Hide latency with animation (wind-up) - Communicate when lag affects gameplay

Anti-Cheat Design

**Cheating** - breaking game rules for an unfair advantage. Aimbots, wallhacks, speed hacks, item duplication. Designer's role: make the game resistant to cheats BY DESIGN, not only through technical solutions.

**Fog of war server-side.** In old RTS games, fog of war was client-side - maphacks simply showed hidden units. Modern games: server doesn't send enemy positions until visible. No data = no hack.

**Design anti-cheat:** - Minimize client authority - Hide information until needed - Validate all critical actions - Design systems robust to exploitation

Matchmaking Systems

**Matchmaking** - a system for pairing players for fair, fun matches. Skill-based (SBMM), connection-based, or hybrid. Goal: minimize one-sided games without long queue times.

**SBMM controversy.** Casual players love it (fair games). Streamers/pros hate it (no stomps for content). COD: hidden SBMM + lobbies disband = constant recalibration. Transparent vs hidden debate.

**Matchmaking design:** - Balance queue time and match quality - Protect new players (separate pools) - Consider parties (premade vs randoms) - Transparency builds trust

Summary

• **Sync vs async** - real-time requires latency compensation. Async = flexible schedule, lower tech requirements
• **Latency design** - client prediction, server reconciliation, lag compensation. Design around latency, not ignore it
• **Anti-cheat** = authoritative server + validation + hide info from client. 'Never trust the client'

Related Topics

Multiplayer fundamentals connect to specific modes:

• Competitive Design — Ranked systems, esports readiness
• Cooperative Design — Co-op specific challenges

Вопросы для размышления

• In which online game did you feel lag the most? How did the game handle (or not handle) it?
• Have you ever been matched against a much stronger opponent? How did it feel?
• If you designed a mobile multiplayer game, sync or async? Why?

Связанные уроки

• gt-01