--- key: mechanic/rpg-grind--duplicate-protection type: mechanic id: rpg-grind--duplicate-protection lang: en title: Duplicate protection summary: >- The system tracks acquired cards when awarding new ones. Hearthstone pack protection limits duplicates within a rarity until its collection requirement is met. updatedAt: '2026-10-22' status: active url: >- https://gamemechanics.pro/en/knowledge/mechanic/rpg-grind--duplicate-protection/ jsonUrl: >- https://gamemechanics.pro/api/v1/knowledge/en/mechanic/rpg-grind--duplicate-protection.json markdownUrl: >- https://gamemechanics.pro/content/knowledge/en/mechanic/rpg-grind--duplicate-protection.md aliases: [] tags: - RPG grinding - Investment and outcome protection sourceIds: - source-e1a5af64e172b78e - source-8cf42d52a93ab613 sources: - id: source-e1a5af64e172b78e title: Hearthstone url: 'https://apps.apple.com/us/app/hearthstone/id625257520?uo=4' verifiedAt: null - id: source-8cf42d52a93ab613 title: 'Hearthstone: duplicate protection, patch 17.0' url: >- https://hearthstone.blizzard.com/en-us/news/23357896/ashes-of-outland-patch-17-0-march-26 verifiedAt: null relations: [] placements: - catalogId: rpg-grind id: duplicate-protection title: RPG grinding url: 'https://gamemechanics.pro/en/mechanics/rpg-grind/#duplicate-protection' categoryIds: - reward-protection supersededBy: [] attributes: preview: updatedAt: '2026-10-22' title: Duplicate protection description: >- The system tracks acquired cards when awarding new ones. Hearthstone pack protection limits duplicates within a rarity until its collection requirement is met. image: src: images/mechanics/rpg-final-hearthstone-4.webp width: 720 height: 333 game: Hearthstone sourceUrl: 'https://apps.apple.com/us/app/hearthstone/id625257520?uo=4' originalUrl: >- https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/8f/a8/ea/8fa8ea66-9f8d-1b20-7830-93b6cee4f11f/e2f76c40-8ad7-48e1-8253-8c8793df8429_bl_hs_2688x1242_set03_s08_JW.jpg/720x1560bb.jpg credit: 'Blizzard Entertainment, Inc.' rights: >- © Blizzard Entertainment, Inc.. Publisher-distributed screenshot or documentation image; all rights reserved. Excluded from portal MIT and CC BY 4.0. caption: 'Hearthstone: a publisher reward composition including a card pack' alt: 'Hearthstone: a publisher reward composition including a card pack' markers: - x: 67 'y': 63 label: Duplicate protection applies to cards when opening these packs tips: - >- Distinguish duplicate protection from rarity odds; they are separate reward rules. examples: - title: Hearthstone url: 'https://apps.apple.com/us/app/hearthstone/id625257520?uo=4' - title: 'Hearthstone: duplicate protection, patch 17.0' url: >- https://hearthstone.blizzard.com/en-us/news/23357896/ashes-of-outland-patch-17-0-march-26 endsAt: null provenance: >- Original editorial RPG grind taxonomy authored for gamemechanics.pro on 2026-10-20 and expanded to cover activities, progression goals, reward rules and constraints. All original thirty family/branch/variant identities are preserved. Official developer and publisher sources support only the specifically described released-game observations; design variants and scenarios are hypothetical. license: CC-BY-4.0 codeLicense: MIT attribution: gamemechanics.pro contributors catalogKey: catalog/rpg-grind --- # Duplicate protection id: rpg-grind--duplicate-protection type: mechanic key: mechanic/rpg-grind--duplicate-protection lang: en status: active url: https://gamemechanics.pro/en/knowledge/mechanic/rpg-grind--duplicate-protection/ The system tracks acquired cards when awarding new ones. Hearthstone pack protection limits duplicates within a rarity until its collection requirement is met. ## At a glance ![Hearthstone: a publisher reward composition including a card pack](https://gamemechanics.pro/images/mechanics/rpg-final-hearthstone-4.webp) [Hearthstone](https://apps.apple.com/us/app/hearthstone/id625257520?uo=4) · © Blizzard Entertainment, Inc.. Publisher-distributed screenshot or documentation image; all rights reserved. Excluded from portal MIT and CC BY 4.0. 1. Duplicate protection applies to cards when opening these packs - Distinguish duplicate protection from rarity odds; they are separate reward rules. - [Hearthstone](https://apps.apple.com/us/app/hearthstone/id625257520?uo=4) - [Hearthstone: duplicate protection, patch 17.0](https://hearthstone.blizzard.com/en-us/news/23357896/ashes-of-outland-patch-17-0-march-26) ## How it works The system tracks previous results and reduces or excludes unwanted duplicates. ## Variants ### Variants - Exclude owned items until a set is complete. - Increase weights for missing categories. - Allow replacement of a duplicate result. ## Design example A collection chest first awards banners not yet obtained. ## Context and limits A systematic RPG grind reference: 110 mechanics and 330 variants in 18 sections. Four layers answer different questions: what the player repeats, what develops, how rewards arrive and what constrains the loop. It covers single-player RPGs, ARPGs, MMORPGs and adjacent management and accumulation systems. Every mechanic has an explanation, variants and a hypothetical example; coverage, combinations and verified game observations follow the catalog. ## Connected materials ## Sources and provenance Original editorial RPG grind taxonomy authored for gamemechanics.pro on 2026-10-20 and expanded to cover activities, progression goals, reward rules and constraints. All original thirty family/branch/variant identities are preserved. Official developer and publisher sources support only the specifically described released-game observations; design variants and scenarios are hypothetical. - [Hearthstone](https://apps.apple.com/us/app/hearthstone/id625257520?uo=4) (id: source-e1a5af64e172b78e) - [Hearthstone: duplicate protection, patch 17.0](https://hearthstone.blizzard.com/en-us/news/23357896/ashes-of-outland-patch-17-0-march-26) (id: source-8cf42d52a93ab613) CC-BY-4.0 · gamemechanics.pro contributors