ICE scoring ranks the items that survive the 80/20 cut by scoring each one from 1 to 10 on three factors, impact, confidence, and ease, then multiplying the three numbers into a single ICE score used for relative ranking [3]. The model was developed by growth practitioner Sean Ellis, and its appeal is speed: a small group can score a backlog in one session and produce a defensible order without heavy analysis [3]. Multiplying rather than adding is deliberate, because a weakness in any one factor should pull the whole score down instead of being averaged away by strength in the others.
Impact
Impact estimates how much the item will move the metric you care about if it works [3]. A homepage headline that greets most of your traffic scores higher than a template change on a page few visitors reach, because impact scales with how many people the change touches and how directly it sits on the path to conversion. Score impact against the sprint's focus metric, not in the abstract, so that an item's impact number answers a specific question: how much would this move demo requests, or trial signups, or whatever the current metric is.
Confidence
Confidence is how sure you are that the impact estimate is right, expressed on the same 1 to 10 scale [3]. It is the factor that keeps optimism honest. An idea backed by session recordings, a prior test result, or a clear analytics signal earns high confidence; an idea that rests on a hunch or a single person's taste earns low confidence, no matter how exciting the impact looks. This is why a plausible big win with weak evidence often ranks below a modest, well-supported change.
Ease
Ease reflects how little effort the item takes to implement, so that quick changes score high and heavy builds score low [3]. Rewriting a headline or shortening a form is a matter of hours; building an interactive calculator or reworking a template system can take weeks. Ease is not a judgment of value, it is a measure of cost, and pairing it with impact and confidence is what surfaces the fast, high-confidence wins a roadmap should front-load.
A worked example on four items that cleared the 80/20 cut:
The pricing calculator scores highest on impact but ranks last, because low confidence and heavy effort multiply against it, which is exactly the caution the model is designed to encode [3]. The headline rewrite wins not because it is the most ambitious idea but because it is high-impact, reasonably certain, and cheap to ship, the profile a roadmap should sequence first. ICE is best used for fast relative prioritization among a handful of contenders rather than as a precise forecast, so treat the scores as a way to order a debate rather than settle it [3]. Rescore at every sprint planning session, because confidence in particular changes as experiments teach you which assumptions held [5].