mtg-online-drafter/docs/development/devlog/2025-12-16-224000_pack_generation_update.md

Pack Generation Algorithm Update

Objective

Update the pack generation logic to match a new 15-slot "Play Booster" structure. The new structure includes:

• Slots 1-6: Commons (Color Balanced).
• Slot 7: Common (87%), List (C/U 10%, R/M 2%), or Special Guest (1%).
• Slots 8-10: Uncommons (3).
• Slot 11: Rare (7/8) or Mythic (1/8).
• Slot 12: Basic Land or Common Dual Land (20% Foil).
• Slot 13: Wildcard (Non-Foil) - Weighted Rarity.
• Slot 14: Wildcard (Foil) - Weighted Rarity.
• Slot 15: Marketing Token / Art Card.

Implementation Details

1. Updated PackGeneratorService.ts:
   • Modified processedPools to explicitly categorize lands (Basic + Common Dual) and tokens.
   • Updated processCards to sort cards into these new pools (instead of filtering them out completely).
   • Rewrote buildSinglePack (for standard rarity mode) to implement the 15-slot sequencing.
   • Implemented logic for:
     • Color balancing commons (naive attempt).
     • "The List" simulation (using Wildcard logic from pools).
     • Slots 13/14 Wildcards with weighted probabilities.
     • Foil application (cloning card and setting finish).
     • Slot 12 Land selection (preferring separate land pool).
   • Added interfaces for typeLine and layout to DraftCard.

Status

• Implemented and Verified via static check (TS linting was fixed).
• Ready for testing in the client.