{
  "slug": "dupe-system",
  "url": "https://gachawiki.com/wiki/dupe-system",
  "type": "term",
  "title": "Dupe system",
  "description": "The mechanics that give duplicate gacha pulls value, such as Genshin Impact's Constellations or Star Rail's Eidolons, where up to six copies unlock upgrades. Dupe systems multiply the ceiling on per-character spending.",
  "aliases": [
    "dupes",
    "constellations",
    "eidolons",
    "limit break"
  ],
  "tags": [
    "terminology",
    "mechanics"
  ],
  "verification": "verified",
  "lastUpdated": "2026-07-09",
  "lastVerified": "2026-07-09",
  "sources": [
    {
      "title": "Genshin Impact in-game character details (Constellation system)",
      "url": "https://genshin.hoyoverse.com/en/home",
      "publisher": "HoYoverse",
      "accessed": "2026-07-09",
      "note": null
    }
  ],
  "related": [
    "whale",
    "powercreep",
    "pity-system",
    "umamusume-pretty-derby"
  ],
  "markdown": "A dupe system gives duplicate copies of a character mechanical value instead of letting them be dead pulls. In [Genshin Impact](/wiki/genshin-impact) duplicates become Constellations, in [Honkai: Star Rail](/wiki/honkai-star-rail) Eidolons, in many Japanese games \"limit breaks\": each additional copy, usually up to six, unlocks a stat boost or ability upgrade. [[1]](#ref-1)\n\nThe design has a quiet economic function: it multiplies the ceiling on what one player can spend on one banner. Fully upgrading a character in a 90-pity, 50/50 game means securing up to seven copies, a worst case of 1,260 pulls, versus 180 for a single copy. Dupe systems are therefore the main lever behind [whale](/wiki/whale)-tier spending, and balance debates often center on how much power is locked behind them.\n\nDesign variation is wide. Support-card games like [Umamusume: Pretty Derby](/wiki/umamusume-pretty-derby) make limit breaks nearly mandatory for competitiveness, because card effects scale steeply with copies. Games like [Blue Archive](/wiki/blue-archive) soften the pressure by letting spark exchanges and farmable shards substitute for pulled duplicates. Where a game sits on that spectrum is one of the better predictors of its long-term cost profile, independent of its headline rates.",
  "license": {
    "name": "CC BY-SA 4.0",
    "url": "https://creativecommons.org/licenses/by-sa/4.0/"
  }
}