Improvements

The formula used to calculate improvements is:

[Perk Value] = [Perk Max] * (1 - exp(-[Amount Invested] / ([Coefficient] * [Land] + 15000)))

The stated maximum below can be exceeded with improvement bonuses such as

Improvement Perks
Bashing
Troll only
  • Defensive power:
    • Max: 50%
    • Coefficient: 7,500
Building
Troll only
  • Construction costs:
    • Max: -50%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -50%
    • Coefficient: 4,000
Cartography
All except Beastfolk, Growth, Troll, Void
  • Exploration gold costs:
    • Max: -35%
    • Coefficient: 4,000
  • Land discovered:
    • Max: 35%
    • Coefficient: 4,000
Coils
Void only
  • Offensive power:
    • Max: 50%
    • Coefficient: 10,000
  • Offensive casualties:
    • Max: -80%
    • Coefficient: 12,000
Commerce
All except Beastfolk, Growth, Troll, Void
  • Gold production:
    • Max: 25%
    • Coefficient: 4,000
Cones
Void only
  • Mana production:
    • Max: 80%
    • Coefficient: 6,000
Construction
Dragon only
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit pairing:
    • Max: 25%
    • Coefficient: 4,000
Construction
Artillery only
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit pairing:
    • Max: 25%
    • Coefficient: 4,000
Construction
Imperial Gnome only
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit pairing:
    • Max: 25%
    • Coefficient: 4,000
Construction
Imperial Gnome only
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit pairing:
    • Max: 25%
    • Coefficient: 4,000
Construction
Qur only
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit pairing:
    • Max: 25%
    • Coefficient: 4,000
Construction
All except Artillery, Beastfolk, Dragon, Growth, Imperial Gnome, Qur, Troll, Void
  • Construction costs:
    • Max: -25%
    • Coefficient: 4,000
  • Rezoning costs:
    • Max: -25%
    • Coefficient: 4,000
Defense
All except Beastfolk, Growth, Troll, Void
  • Defensive power:
    • Max: 25%
    • Coefficient: 7,500
Espionage
All except Beastfolk, Growth, Troll, Void
  • Spy strength:
    • Max: 45%
    • Coefficient: 5,000
  • Reduced spy losses:
    • Max: -45%
    • Coefficient: 5,000
  • Forest Haven housing:
    • Max: 45%
    • Coefficient: 5,000
Farming
All except Armada, Beastfolk, Growth, Troll, Void
  • Food production:
    • Max: 45%
    • Coefficient: 5,000
Forestry
Wood Elf only
  • Lumber production:
    • Max: 25%
    • Coefficient: 4,000
  • Population growth:
    • Max: 35%
    • Coefficient: 6,000
Glimmering
Troll only
  • Gold production:
    • Max: 50%
    • Coefficient: 4,000
Halo
Void only
  • Defensive power:
    • Max: 25%
    • Coefficient: 6,000
  • Defensive casualties:
    • Max: -50%
    • Coefficient: 8,000
Harbour
Armada only
  • Food production:
    • Max: 45%
    • Coefficient: 5,000
  • Unit pairing:
    • Max: 45%
    • Coefficient: 5,000
Haze
Void only
  • Unit mana costs:
    • Max: -20%
    • Coefficient: 6,000
Housing
All except Beastfolk, Growth, Troll, Void
  • Population:
    • Max: 20%
    • Coefficient: 4,000
Hunting
Troll only
  • Food production:
    • Max: 90%
    • Coefficient: 5,000
Logging
All except Beastfolk, Growth, Sylvan, Wood Elf, Troll, Void
  • Lumber production:
    • Max: 25%
    • Coefficient: 4,000
Medicine
All except Beastfolk, Growth, Troll, Void
  • Defensive casualties:
    • Max: -25%
    • Coefficient: 4,000
  • Offensive casualties:
    • Max: -25%
    • Coefficient: 4,000
Mobilisation
All except Beastfolk, Growth, Troll, Void
  • Unit gold costs:
    • Max: -25%
    • Coefficient: 4,000
  • Unit ore costs:
    • Max: -25%
    • Coefficient: 4,000
Muttering
Troll only
  • Wizard strength:
    • Max: 90%
    • Coefficient: 5,000
  • Mana production:
    • Max: 90%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -90%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 90%
    • Coefficient: 5,000
Nesting
Troll only
  • Population:
    • Max: 40%
    • Coefficient: 4,000
Offense
All except Beastfolk, Growth, Troll, Void
  • Offensive power:
    • Max: 25%
    • Coefficient: 7,500
Prism
Void only
  • Population:
    • Max: 100%
    • Coefficient: 100,000
  • Population growth:
    • Max: 50%
    • Coefficient: 50,000
Research
All except Beastfolk, Growth, Troll, Void
  • XP generation:
    • Max: 25%
    • Coefficient: 5,000
  • XP gained:
    • Max: 25%
    • Coefficient: 5,000
Rock Throwing
Troll only
  • Ore production:
    • Max: 50%
    • Coefficient: 4,000
Smashing
Troll only
  • Offensive power:
    • Max: 50%
    • Coefficient: 7,500
Sneaking
Troll only
  • Spy strength:
    • Max: 90%
    • Coefficient: 5,000
  • Reduced spy losses:
    • Max: -90%
    • Coefficient: 5,000
  • Forest Haven housing:
    • Max: 90%
    • Coefficient: 5,000
Stonecutting
All except Beastfolk, Growth, Troll, Void
  • Ore production:
    • Max: 25%
    • Coefficient: 4,000
Tissue
Growth only
  • Population:
    • Max: 100%
    • Coefficient: 75,000
  • Food production:
    • Max: 100%
    • Coefficient: 75,000
Training
Troll only
  • Unit gold costs:
    • Max: -50%
    • Coefficient: 4,000
  • Unit ore costs:
    • Max: -50%
    • Coefficient: 4,000
Trampling
Troll only
  • Land discovered:
    • Max: 70%
    • Coefficient: 4,000
Uprooting
Troll only
  • Lumber production:
    • Max: 50%
    • Coefficient: 4,000
Waves
Void only
  • Unit training time:
    • Max: -80%
    • Coefficient: 12,500
  • Chance of units returning instantly from invasion:
    • Max: 50%
    • Coefficient: 25,000
Wizardry
All except Beastfolk, Growth, Nox, Qur, Reptilians, Troll, Undead, Void
  • Wizard strength:
    • Max: 45%
    • Coefficient: 5,000
  • Mana production:
    • Max: 45%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -45%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 45%
    • Coefficient: 5,000
Wizardry
Nox only
  • Wizard strength:
    • Max: 45%
    • Coefficient: 5,000
  • Mana production:
    • Max: 45%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -45%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 45%
    • Coefficient: 5,000
  • Unit pairing:
    • Max: 45%
    • Coefficient: 5,000
Wizardry
Qur only
  • Wizard strength:
    • Max: 45%
    • Coefficient: 5,000
  • Mana production:
    • Max: 45%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -45%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 45%
    • Coefficient: 5,000
  • Unit pairing:
    • Max: 90%
    • Coefficient: 5,000
Wizardry
Reptilians only
  • Wizard strength:
    • Max: 45%
    • Coefficient: 5,000
  • Mana production:
    • Max: 45%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -45%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 45%
    • Coefficient: 5,000
  • Unit pairing:
    • Max: 45%
    • Coefficient: 5,000
Wizardry
Undead only
  • Wizard strength:
    • Max: 45%
    • Coefficient: 5,000
  • Mana production:
    • Max: 45%
    • Coefficient: 5,000
  • Spell damage:
    • Max: -45%
    • Coefficient: 5,000
  • Wizard Guild housing:
    • Max: 45%
    • Coefficient: 5,000
  • Unit pairing:
    • Max: 45%
    • Coefficient: 5,000