02Retention

Energy / Lives

A system that limits how many attempts or sessions a user can have within a given time window.

Best for
Achiever
Context
RetentionMonetization
Motivation drivers
ScarcityAvoidance
How it works

Scarcity creates perceived value

Each action consumes one unit. When depleted, the session ends until units regenerate, are gifted by friends, or purchased. The mechanic functions as both a pacing tool and a monetisation surface, with depletion as the primary purchase trigger. Scarcity creates value, play that can continue indefinitely is taken for granted.

Core principle

Scarcity creates perceived value. The moment of depletion is engineered to coincide with peak engagement desire.

Watch out for

Energy systems feel punishing in long-form apps. The regeneration timer must feel fair, too slow and users churn; too fast and scarcity loses meaning.

Structural variants

Three ways to build it

01

Fixed capacity with timed regen

02

Lives lost on failure

03

Energy gifting between users

Lifecycle placement

Early-to-mid engagement before habitual use is established.

Case studies · 3

Seen in the wild

Capybara Go!Roguelite
How they use it

Each run costs 5 energy. The cap is 30 energy, regenerating over time. Multiple acquisition methods: rewarded video ads (up to 15 energy, twice daily), gem purchases (15 energy for 90 gems, four times daily), and a daily free pack of 10 energy on a 5-hour refresh. The energy overflow mechanic stores regenerated energy above the cap in an inbox as claimable messages for up to six days. On returning after a long absence, 249 energy units were waiting, equivalent to nearly 50 runs.

Why it works

The overflow inbox inverts the standard energy mechanic: instead of punishing absence (missed regeneration above the cap is wasted), the game rewards it by storing everything. A returning player after a week away finds a full inbox of accumulated energy rather than a capped counter. Returning feels abundant rather than penalized.

The detail

Energy is displayed as a counter in the home screen UI. The inbox stores overflow energy as messages claimable on return. Each energy acquisition method is a distinct interaction rather than a single button.

Takeaway

Energy overflow above the 30-unit cap is stored in the inbox as claimable messages for up to six days, inverting the standard energy mechanic by rewarding absence rather than penalizing it.

Chrome Valley CustomsPuzzle / Meta
How they use it

Players start with 5 hearts. Each failed match-3 level costs one heart. The session never reached a hard heart block because the Rig's Road Trip event awarded 30 minutes of infinite health before natural exhaustion occurred, the energy system was visible throughout but was not experienced as a blocker in the first episode. Multiple sources of infinite health were available from the start: from event rewards (30 minutes), from store bundles (1 hour, 6 hours, 18 hours), and from standalone store packages.

Why it works

Granting infinite health through event participation before the natural energy cap is reached removes the hard blocker from the new user experience entirely. The player is aware of the energy system but does not experience its constraint during their first episode, a deliberate design choice to maximize content exposure before monetization pressure begins.

The detail

Hearts display in the top bar alongside coins and gems. When infinite health is active, a countdown timer shows the remaining duration. The infinite health award from the event was delivered narratively by the guide character, framing it as a game reward rather than a monetization prompt.

Takeaway

The event reward (30 minutes infinite health) preceded natural heart exhaustion, meaning the energy system was never experienced as a blocker during Episode 1, a deliberate new-player design choice.

Royal MatchCasual Game
How they use it

Players start with five hearts. Each failed level costs one heart. Hearts regenerate at one every approximately 25 minutes. When depleted, the lives screen shows: time to next life, a free lives request option (request from teammates), and a refill option costing 900 gold coins. The first heart depletion was timed to the difficulty spike around levels 19–21, the first genuinely challenging levels. The Easter Pass raises the heart cap from five to eight.

Why it works

The mechanic is timed, not constant. The wall at the moment a player has failed twice reads as natural frustration with a clear solution. Both the spend prompt and the social team path arrive at the same moment of peak desire to continue, making the team mechanic feel like a natural remedy rather than a feature to discover.

The detail

Hearts display as a row in the top bar from the start. When lives run low during a level, the King character visually expresses concern. The lives screen routes the depleted player to Ask Your Teammates first, the 900-coin refill is the secondary option. A 'hard level' label appears at level 39, signaling failure is by design rather than player error.

Takeaway

The team join prompt appears at the precise moment the energy system first becomes painful, levels 19–21, the first difficulty spike, making the social mechanic feel like a solution to a problem the player already has.