Clamp rarity redistribution rates at zero #529

New issue

Open

opened 2026-09-15 12:26:13 +01:00 by Smithy-bot · 0 comments

Smithy-bot commented

2026-09-15 12:26:13 +01:00

Member

Spun out of the non-blocking review note on PR #527.

Why

Rarity chance-up redistribution doubles the active rarity rate and spreads the delta across the other four rarities. For large boosts, that can drive other rarity buckets below zero (already noted in docs/effects.md). Current behaviour is acceptable for merge, but clamping at 0 would make the math safer and avoid negative rates.

Suggested approach

In the rarity redistribution logic (e.g. GetCardsHelper), clamp redistributed rarity rates so no bucket goes below 0.
Decide how leftover delta is handled when clamping would leave remaining probability unaccounted for (renormalise, absorb into the boosted rarity, or another explicit rule).
Add/adjust unit tests for large boosts that previously produced negative buckets.
Update docs/effects.md so the documented edge case matches the new clamping behaviour.

Notes

Source: #527 (comment)

Spun out of the non-blocking review note on PR #527. ## Why Rarity chance-up redistribution doubles the active rarity rate and spreads the delta across the other four rarities. For large boosts, that can drive other rarity buckets below zero (already noted in `docs/effects.md`). Current behaviour is acceptable for merge, but clamping at 0 would make the math safer and avoid negative rates. ## Suggested approach 1. In the rarity redistribution logic (e.g. `GetCardsHelper`), clamp redistributed rarity rates so no bucket goes below 0. 2. Decide how leftover delta is handled when clamping would leave remaining probability unaccounted for (renormalise, absorb into the boosted rarity, or another explicit rule). 3. Add/adjust unit tests for large boosts that previously produced negative buckets. 4. Update `docs/effects.md` so the documented edge case matches the new clamping behaviour. ## Notes - Source: https://git.vylpes.xyz/External/card-drop/pulls/527#issuecomment-21271

Smithy-bot added the

labels

2026-09-15 12:26:13 +01:00

Smithy-bot self-assigned this

2026-09-15 12:26:13 +01:00