Best Practices

Feature Flags for Games: Beyond Simple Toggles

Advanced feature flag patterns that help you ship faster and roll back safely.

JK
Jordan Kim/January 8, 2025/6 min read
Feature AFeature BFeature CDisabled

Most developers first encounter feature flags as simple boolean toggles, a way to hide unfinished code behind an if statement until it is ready to ship. That mental model works fine for web applications. Games are different. A broken rollout during a live tournament can trigger mass player churn and revenue loss measured in hours. Feature flags in games need to do more than flip bits.

This post covers the advanced patterns game studios actually rely on: JSON configuration flags, canary releases, segment-based targeting, and lifecycle management. If you are still treating flags as a development convenience, it is time to rethink them as a runtime control plane for your live game.

The Flag Types Games Actually Use

The boolean flag is table stakes. Games need two additional types that rarely appear in generic feature flag guides.

Boolean Flags
Straightforward on/off toggles: new_tutorial_enabled, maintenance_mode, holiday_lobby_active. The simplest type, but only the starting point.
Multivariate Flags
Distribute players across multiple variants with weighted percentages. Test store layouts, difficulty curves, or matchmaking algorithms without separate builds.
JSON Flags
Carry full configuration objects: enemy_health_multiplier, loot_drop_rate, respawn_time_seconds. Remotely adjust game balance without a client update.

Boolean flags handle the straightforward cases: new_tutorial_enabled, maintenance_mode, holiday_lobby_active. On or off.

Multivariate flags distribute players across multiple variants with weighted percentages. A store_layout flag might assign 40% of players to variant A, 40% to variant B, and 20% to variant C. This is the backbone of A/B testing game mechanics, letting you test difficulty curves or matchmaking algorithms without separate builds.

Multivariate Flag: store_layout
Variant A
40%
Variant B
40%
Variant C
20%

JSON flags are where games diverge from web applications entirely. A single difficulty_config flag can carry a full configuration object: enemy_health_multiplier, loot_drop_rate, respawn_time_seconds, and any other tunable parameter. This lets you remotely adjust game balance and economy without a client update. That matters when your mobile game is subject to app store review or your console build requires certification.

These flag types give the entire LiveOps team a remote configuration and experimentation layer, not just a developer toggle.

Game-Specific Patterns That Matter

Scheduled Flags for Live Events

Seasonal events and limited-time modes drive modern LiveOps. Rather than deploying code at midnight to activate holiday content, ship the content in advance and let a scheduled flag handle activation.

A winter_event flag with enable and disable timestamps will activate and deactivate on its own. No deploy, no engineer on call. The content is already in the client; the flag controls visibility. Combine this with segment targeting to give VIP players a 24-hour early preview.

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Create
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Test
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Canary
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Ramp
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Full
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Cleanup

Kill Switches for Every Risky Feature

Every new multiplayer mode, payment flow, or matchmaking algorithm should be wrapped in a kill switch: a flag that, when disabled, immediately returns a safe default value without evaluating any targeting rules.

Kill Switch Discipline
If a new boss encounter is causing server crashes at 2 AM, a single dashboard toggle reverts every player to the safe experience instantly. No hotfix, no deploy. The key discipline is deciding what “safe default” means for each feature before you ship it. That five-minute conversation during development can save hours of incident response.

Canary Releases That Protect Live Players

A player in the middle of a ranked match cannot tolerate a crash. The stakes of a bad rollout in games are higher than in most web applications, which makes canary releases worth the effort.

Deploy your new code to all servers behind a disabled flag. Enable it for 1% of players, your canaries. Monitor crash rates, error rates, and latency for that cohort. If metrics hold, ramp to 5%, then 10%, 25%, 50%, 100%. If anything degrades at any step, disable the flag and every player instantly reverts.

0%
Initial canary cohort
0%
First ramp after validation
0%
Intermediate checkpoint
0%
Full rollout

Deterministic hashing makes this work smoothly. A hash of the player ID produces a stable bucket assignment, so the same player always sees the same experience across sessions. Progressive rollout schedules can automate the ramp further: define a schedule from 5% to 100% over a week, with an automatic pause if the error rate exceeds a threshold.

Targeting Beyond “On” and “Off”

The real power of game feature flags comes from combining them with player segmentation. Segments define who sees something; flags define what they see. Targeting rules bridge the two.

Targeting DimensionPlayer AttributesExample Use Case
Spending TierTotal revenue, purchase count, predicted LTVPremium store experience for whales; retention offers for high-value churning players
Progression & LifecycleLevel, sessions played, lifecycle stageEndgame content gated to level 50+; competitive modes disabled for first 5 sessions
Region & DeviceCountry, device model, OS versionSoft-launch in PH/NZ; disable effects on low-end devices; comply with regional regulations
Combined ConditionsAND/OR groups with priority orderingActive US players OR any player with $500+ spend, first matching rule wins

By Spending Tier

Target high-value players with a premium store experience, or test different pricing across spending tiers. Player attributes like total revenue, purchase count, and predicted lifetime value make this straightforward. You can also combine spending data with churn risk scores to surface retention offers to high-value players showing signs of disengagement.

By Progression and Lifecycle

Only show endgame content to players past level 50. Disable competitive modes for players in their first five sessions. Lifecycle-stage targeting (new, active, engaged, at-risk, churned, returned) lets you tailor the experience to where each player actually is in their time with your game.

By Region and Device

Soft-launch in the Philippines and New Zealand before a global rollout. Disable graphically intensive effects on low-end devices. Comply with regional regulations by disabling loot box mechanics where required. For any game with a global audience, these are standard operating procedures.

Combining Conditions

Real targeting is rarely single-dimensional. You might want to show a feature to active players in the US, or to any player who has spent more than $500 regardless of region. Nested AND/OR condition groups with priority-based rule ordering let you express this without it becoming unmanageable. First matching rule wins.

Lifecycle Management: The Discipline Most Teams Skip

Every active feature flag adds a conditional branch to your codebase, one that needs to be tested, understood, and maintained. Uber built an automated tool called Piranha specifically to remove stale flags from their mobile apps after accumulating roughly 2,000 of them. That is the scale of the problem when cleanup is an afterthought.

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Stale flags Uber accumulated before building Piranha
0%
Full rollout threshold before cleanup begins
0 days
Maximum time a fully-rolled-out flag should persist

A flag has a natural lifecycle: created, tested with QA, canary-released, ramped to full rollout, and then cleaned up. The cleanup step is where most teams fail. The flag is at 100%, the feature works, and there is always something more urgent than removing dead code paths.

Practices that make cleanup sustainable:

1
Set expiration dates at creation time
When you create a flag, pick a calendar date for code removal. Tag it accordingly, like cleanup-q1-2026.
2
Remove flag code within 30 days of full rollout
If a flag has been at 100% for over 30 days, it is dead code with a configuration layer on top.
3
Distinguish permanent from temporary flags
Kill switches, entitlement flags, and regulatory compliance flags live forever. Everything else has an expiration date.
4
Automate stale flag detection
Use dashboards or alerts to surface flags that have been fully rolled out beyond their expiration window.

Server-Side Evaluation: Keep Your Logic Private

Always evaluate flags server-side. Client-side evaluation means shipping your targeting rules and player data into an environment players can inspect and tamper with.

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Client Request
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Server Receives
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Evaluate Rules
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Cache Result
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Return Values

With server-side evaluation, the client sends a player identifier. The server evaluates all rules against the full profile and returns only the final values, never the logic. The SDK caches results locally for zero-latency reads during gameplay, refreshing asynchronously without blocking the game loop. One bulk evaluation call at session start populates the entire cache.

Why Server-Side Matters
Server-side evaluation keeps your targeting rules, player segmentation logic, and experiment configurations private. The client only ever sees the resolved flag values, never the decision-making process behind them.

From Toggle to Control Plane

Feature flags started as a way to hide unfinished work. For game studios running live services, they have become a runtime control plane that governs what players experience, when they experience it, and how safely new changes roll out.

The difference between a studio that ships with confidence and one that dreads every update often comes down to the maturity of their flag practices. The right flag types, progressive rollouts, precise targeting, and disciplined cleanup. These are the patterns behind studios that ship weekly and treat every release as a controlled experiment.

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