Eonevolve Learning
Economy DesignSystem and economyIntermediate~6 min

Currency sink catalog

Snapshot

~80 sec

A sink catalog is the list of things a currency can be spent on. Sort each sink into cosmetic, convenience, power, or time-skip first, then hand it to soft or hard currency based on which trust boundary it would cross.

You will learn

  • Sort a proposed purchase into cosmetic, convenience, power, or time-skip.
  • Decide which of those four categories hard currency can safely own.
  • Spot the one swap that breaks the earned-versus-paid trust boundary.

Target outcome

You can look at a list of proposed purchases and assign each one to soft or hard currency without breaking the trust boundary between them.

Visual walkthrough

Visual walkthrough

~6 min

  1. Four sink categories, before any currency is assigned

    • Cosmetic

      Changes appearance only. No effect on power or pace.

    • Convenience

      Removes friction - extra inventory space, sorting, small quality-of-life.

    • Power

      A real advantage inside the core loop: stronger, faster, more efficient.

    • Time-skip

      Instantly finishes a timer that would otherwise pass on its own.

  2. Which currency should own which sink

    ApproachOwns itWhyIf you swap it
    Soft currencyEarned through play; carries the core progression.Power and most time-skip sinks - the ones that gate how fast a player advances.Progress bought with play time is the thing players are trusting the game to reward fairly.Moving power to hard currency turns skill or time investment into a purchase, which is the fastest way to make earned progress feel worthless.
    Hard currencyPaid; carries cosmetic and convenience.Cosmetic sinks and convenience sinks that don't change the core loop's difficulty or pace.Paying for looks or comfort doesn't cost another player anything, so the trust boundary stays intact.Moving cosmetics to soft currency just makes hard currency feel pointless - a wasted opportunity, not a broken trust boundary.
  3. Classify a proposed purchase

    A shop offers to instantly max out a character's core stat for hard currency. Which category is this, and where does the trust boundary say it should live?

    Expected reasoning

    This is a power sink, not a time-skip or cosmetic one - it changes what the character can do, not just when or how it looks. Power sinks belong on soft currency; selling one for hard currency crosses the earned-versus-paid boundary this catalog is built to protect.