{
  "iron_region_system": {
    "resource_type": "iron_ore",
    "description": "Iron feature selection based on region mass and biome compatibility",

    "features": {
      "rich_iron_ore": {
        "display_name": "Rich Iron Ore",
        "incompatible_biomes": ["tropical_rainforest", "wetlands"],
        "frequent_biomes": ["hills", "rocky_plateau", "alpine"],
        "minimum_region_mass": 150,
        "quality_base": "premium",
        "extraction_difficulty": "medium",
        "budget_impact": 4,
        "description": "High-grade iron ore requiring strong geological activity"
      },

      "iron_ore_vein": {
        "display_name": "Iron Ore Vein",
        "incompatible_biomes": ["tropical_rainforest", "wetlands"],
        "frequent_biomes": ["hills", "rocky_plateau", "alpine", "temperate_forest"],
        "minimum_region_mass": 75,
        "quality_base": "standard",
        "extraction_difficulty": "medium",
        "budget_impact": 3,
        "description": "Standard iron ore in medium-strength regions"
      },

      "magnetite_deposit": {
        "display_name": "Magnetite Deposit",
        "incompatible_biomes": ["wetlands", "hot_desert"],
        "frequent_biomes": ["hills", "rocky_plateau", "alpine"],
        "minimum_region_mass": 50,
        "quality_base": "premium",
        "extraction_difficulty": "easy",
        "budget_impact": 3,
        "description": "Magnetic iron ore accessible in moderate regions"
      },

      "hematite_outcrop": {
        "display_name": "Hematite Outcrop",
        "incompatible_biomes": ["tropical_rainforest", "wetlands"],
        "frequent_biomes": ["hills", "rocky_plateau", "grassland", "scrubland"],
        "minimum_region_mass": 25,
        "quality_base": "standard",
        "extraction_difficulty": "easy",
        "budget_impact": 2,
        "description": "Surface iron ore available in small regions"
      },

      "laterite_iron": {
        "display_name": "Laterite Iron",
        "incompatible_biomes": ["alpine", "cold_desert", "tundra", "hot_desert"],
        "frequent_biomes": ["tropical_rainforest"],
        "minimum_region_mass": 30,
        "quality_base": "medium",
        "extraction_difficulty": "hard",
        "budget_impact": 2,
        "description": "Tropical weathering iron, specialized formation"
      },

      "bog_iron": {
        "display_name": "Bog Iron",
        "incompatible_biomes": ["hot_desert", "cold_desert", "alpine", "rocky_plateau"],
        "frequent_biomes": ["wetlands"],
        "minimum_region_mass": 10,
        "quality_base": "low",
        "extraction_difficulty": "very_easy",
        "budget_impact": 1,
        "description": "Low-grade iron in wetland environments"
      },

      "taconite": {
        "display_name": "Taconite",
        "incompatible_biomes": ["tropical_rainforest", "wetlands", "hot_desert"],
        "frequent_biomes": ["hills", "rocky_plateau", "grassland"],
        "minimum_region_mass": 200,
        "quality_base": "low",
        "extraction_difficulty": "hard",
        "budget_impact": 2,
        "description": "Low-grade iron requiring very large, stable regions"
      }
    },

    "selection_logic": {
      "step_1": "Check region mass against minimum_region_mass",
      "step_2": "Filter out features with incompatible biomes",
      "step_3": "Prioritize features with frequent biomes for this location",
      "step_4": "Select from available features",
      "fallback": "If no features available, place generic iron_ore"
    },

    "mass_categories": {
      "tiny_region": {"mass_range": [10, 30], "typical_features": ["bog_iron", "laterite_iron"]},
      "small_region": {"mass_range": [30, 75], "typical_features": ["hematite_outcrop", "magnetite_deposit"]},
      "medium_region": {"mass_range": [75, 150], "typical_features": ["iron_ore_vein", "magnetite_deposit"]},
      "large_region": {"mass_range": [150, 300], "typical_features": ["rich_iron_ore", "iron_ore_vein"]},
      "huge_region": {"mass_range": [300, 1000], "typical_features": ["rich_iron_ore", "taconite"]}
    }
  }
}