THE SHORT ANSWER
Roblox launched two new experiment metric sets — Custom and Rewarded Video Ads — letting developers measure game-specific events and ad performance alongside standard retention and ARPU data.
- Custom metric set supports up to three metrics built from AnalyticsService custom, economy, or funnel events
- Rewarded Video Ads metric set tracks impressions, engagement, and ad revenue per user versus total revenue
- Metrics configured in Creator Hub > Configure > Experiments > Create experiment
- Custom metrics count each player once over the full experiment, differing from daily Analytics views
- Statistical significance still required before acting on results
Two New Metric Sets Arrive for Experiments
Roblox has added two dedicated metric sets to its experiment framework, giving creators a way to measure changes against the specific mechanics that drive their games. Until now, every experiment reported the same top-line numbers — playtime, retention, ARPU — regardless of what the test actually changed. The update, posted to the Developer Forum on November 12, introduces a Custom metric set and a Rewarded Video Ads metric set, both selectable when creating a new experiment in Creator Hub.
Custom Metrics: Build Around Your Game's Core Loops
The Custom metric set lets developers add up to three metrics derived from events they already log via AnalyticsService. Sources include Custom events, Economy events (currency sinks and sources), and Funnel events (step-by-step progression). For each metric, creators pick a source, define the measurement target — a specific event, currency, or funnel step — choose a calculation method such as average value or participation rate, and optionally apply filters.
One metric is designated the primary goal; the others become learning metrics tracked alongside standard outcomes. The announcement includes concrete examples: measuring onboarding funnel completion when shortening a tutorial, tracking QuestStarted participation after adding a daily quests button, comparing average coin sink delta on a specific SKU after a price change, and monitoring net coin delta when doubling daily login rewards. Metrics can be reused across experiments via an "Add from past experiments" button.
Rewarded Video Ads: Test Placement and Revenue Impact
The Rewarded Video Ads metric set addresses a long-standing blind spot. Rewarded ads can lift revenue from non-spending players, but placement, reward value, and economy integration all affect whether they help or hurt. The new set surfaces reach, impressions per user, and ads revenue per user, then compares ads revenue directly against total revenue so creators can see if ads are incrementally adding earnings or cannibalizing other streams.
How to Access and What to Watch For
Both metric sets live under Creator Hub > Configure > Experiments > Create experiment. The announcement flags two practical caveats. First, experiment metrics aggregate over the full run and count each player once, while Analytics defaults to a daily view — numbers will differ. Use Analytics to verify event firing, then rely on experiment results for variant comparison. Second, custom metrics need sufficient sample size for statistical significance; insignificant moves should not drive decisions.
The rollout is live now. No client update is required; the changes are server-side in the experiment configuration UI.