in Kingdom Rush are used to increase the power and effectiveness of towers and spells. There are six upgrade trees, one for each tower type and one for each spell. Each tree has a total of five upgrades.


Upgrades are bought with stars, which can be obtained in several ways:

  • Completing a Campaign level gives stars based on the number of lives left:
    • 18+ lives: 3 stars
    • 6-17 lives: 2 stars
    • 1-5 lives: 1 star
  • Completing a Heroic Challenge or Iron Challenge gives 1 star.
  • Exclusive to the Flash version:
    • Buying the Premium Content gives 15 stars.
    • Clicking on the Twitter and Facebook buttons gives 1 star each.
    • Trivia
    • You need to get 65 (62 stars on Flash) stars to buy every upgrade on all six trees in the original Kingdom Rush.

Kingdom Rush

Archer Tower

  • KR Up Salvage Salvage (1 Star): Marksmen Towers return 90% of value when sold. (Normally a rate of return is 60%.)
  • KR Up EagleEye Eagle Eye (1 Star): Increases Marksmen attack range (by 10%).
  • KR Up PierSht Piercing Shots (2 Stars): Piercing shots ignore a portion of the enemy's physical armor. (1/4)
  • KR Up FarShot Far Shots (2 Stars): Increases marksmen attack range (by 10%).
  • KR Up Presc Precision (3 Stars): Marksmen attacks have a chance of dealing double damage. (10%)


  • KR Up Tough Toughness Training (1 Star): Barracks train soldiers with more health. (+10% health)
  • KR Up BetArmor Better Armor (1 Star): Barracks train soldiers with improved armor. (+10% armor)
  • KR Up ImpDep Improved Deployment (2 Stars): Improves rally point range (by 20%) and reduces soldier training time. (Respawn time is reduced by 3 seconds for Holy Order, and by 2 seconds for the others.)
  • KR Up EndTrain Endurance Training (2 Stars): Barracks train soldiers with even more health. (+20% health of the main one)
  • KR Up Spiked Spiked Armor (3 Stars): When attacked, soldier's spiked armor return a percent of the damage received to the attacker. Spiked Armor also affects Reinforcements and Heroes. (~12.5% reflection of damage, dealt as True Damage)

Magic Tower

  • KR Up SpellReach Spell Reach (1 Star): Increases wizard's attack range (by 10%).
  • KR Up ArcShatt Arcane Shatter (1 Star): Magic attacks destroy a potion of enemy physical armor on every hit. (-3% armor per hit, doesn't work on enemies with physical damage immunity.)
  • KR Up Heremtic Hermetic Study (2 Stars): Mage Towers construction and upgrading costs are reduced by 10%.
  • KR Up EmpMagic Empowered Magic (2 Stars): Increases wizard's attack damage. (about 15%)
  • KR Up SlowCurse Slow Curse (3 Stars): Magic attacks slow enemies by half their speed for a moment (half a second, Arcane Wizard the whole one-second beam duration. Also disables Rocket Rider Turbo boost).


  • KR Up ConcFire Concentrated Fire (1 Star): Increases artillery attack damage (10% damage increase).
  • KR Up Range Range Finder (1 Star): Increases artillery attack range (by 10%).
  • KR Up FieldLog Field Logistic (2 Stars): Artillery construction and upgrading costs are reduced by 10%.
  • KR Up Indust Industrialization (3 Stars): Artillery special abilities costs are reduced by 25%.
  • KR Up SmartTar Smart Targeting (3 Stars): Artillery suffers no reduction of splash and chain lightning damage. (Means the damage is not reduced by distance from the center of explosion or between targets of Tesla x104 electric bolt.)

Rain of Fire

  • KR Up BlazSky Blazing Skies (1 Stars): Adds 2 additional meteors and increases meteor damage.
  • KR Up Scorch Scorched Earth (2 Stars): Meteors set the ground on fire burning enemies over it for 5 seconds.
  • KR Up FastFur The Fast & Furious (3 Stars): Increases meteor damage, explosion radius by 25% and reduces cooldown by 10 seconds.
  • KR Up BlazEarth Blazing Earth (3 Stars): Doubles damage and duration of scorched earth, and reduces cooldown by 10 seconds.
  • KR Up Catac Cataclysm (3 Stars): Increases meteor damage and rains 5 additional meteors at random locations all over the battlefield.


  • KR Up WellFed Well Fed (2 Stars): Well Fed Farmers have additional health and deal a little more damage. (50 HP, 1-3 damage)
  • KR Up Consc Conscripts (3 Stars): Conscripts have more health and are better equipped. (70 HP, 10% armor, 2-4 damage)
  • KR Up Warr Warriors (3 Stars): Warriors have even more health and are excellently equipped. (90 HP, 20% armor, 3-6 damage)
  • KR Up Legion Legionnaires (3 Stars): Legionnaires have the most health and wear the best equipment. (110 HP, 30% armor, 6-10 damage)
  • KR Up SprThrw Spear Throw (4 Stars): Gives Legionnaires a spear throw attack that can target ground and flying enemies. (110 HP, 30% armor, 6-10 damage, 24-40 ranged damage)

Kingdom Rush: Frontiers

Archer Tower

  • Up KRF ImpAim Steady Hand (1 Star): Increases marksmen attack range (by 10%).
  • Up KRF Lumbermill Lumbermill (1 Star): Reduces basic archer construction costs. (-10 gold for level 1-3 archer towers).
  • Up KRF FocusAim Focused Aim (2 Stars): Increases marksmen attack damage. (1-2 damage).
  • Up KRF Accuracy Accuracy (2 Stars): Increases marksmen attack range (by 5%) and damage (1-5 damage).
  • Up KRF TwinShot Twin Shot (3 Stars): Marksmen have a chance of shooting two projectiles at the same time. (10%)


  • Up KRF Stance Defensive Stance (1 Star): Barracks train soldiers with better armor. (+10% armor)
  • Up KRF BootCamp Boot Camp (1 Star): Barracks train more resilient soldiers. [HP +10%]
  • Up KRF Espirt Esprit de Corps (2 Stars): Increases barrack rally point range (+20%) and healing rate (+20% per second).
  • Up KRF Veteran Veteran Squad (2 Stars): Soldiers are trained faster and with improved armor. (-2 seconds of respawn time, +10% armor of the main one)
  • Up KRF Courage Courage (3 Stars): While in combat, soldiers, mercenaries & reinforcements regenerate health. (It doesn't when under area attack.)

Magic Tower

  • Up KRF Rune Rune of Power (1 Star): Increases mages' attack range (by 10%).
  • Up KRF Penetration Spell Penetration (1 Star): Mages' bolts have a chance to ignore magic resistance. (10%)
  • Up KRF Eldritch Eldritch Power (2 Stars): Increases mages' attack damage (by 10%).
  • Up KRF Academy Wizard Academy (2 Stars): Reduces mages' special abilities costs by 10%.
  • Up KRF Brilliance Brilliance (3 Stars): For every other mage tower built, each mage tower gets a bonus to damage (+5% per tower beyond the first, to a maximum of +30%).


  • Up KRF Smoothbore Smoothbore (1 Star): Increases artillery attack range (by 10%).
  • Up KRF Powder Alchemical Powder (1 Star): Artillery has a chance of dealing maximum damage with no splash reduction.
  • Up KRF Ordnance Improved Ordnance (2 Stars): Increases artillery attack damage (by 10%).
  • Up KRF Gnomish Gnomish Tinkering (3 Stars): Reduces artilleries' special abilities reload times.
  • Up KRF ShockAwe Shock and Awe (3 Stars): Artillery towers have a chance of stunning their targets on every attack.

Rain of Fire

  • Up KRF Burning Burning Skies (2 Stars): Increases meteor damage and reduces cooldown by 5 seconds.
  • Up KRF Scorched Scorched Earth (2 Stars): Meteors set the ground on fire for 5 seconds, burning enemies walking over it.
  • Up KRF Hellfire Hellfire (3 Stars): Adds 2 additional meteors and reduces cooldown by 5 seconds.
  • Up KRF Conflagration Conflagration (3 Stars): Increases meteor damage and explosion radius (+25%) while doubling scorched earth effects.
  • Up KRF Cataclysm Cataclysm (3 Stars): Increases meteor damage and rains 4 additional meteors at random locations all over the battlefield.


  • Up KRF Trained Trained Volunteers (2 Stars): Trained Volunteers have additional health and deal a little more damage. (50 HP, 1-3 damage)
  • Up KRF MenatArms Men-at-Arms (3 Stars): Men-at-Arms have more health and wear good armor. (70 HP, 10% armor, 2-4 damage)
  • Up KRF Champion Champion (3 Stars): Champions have even more health and wield great weapons. (90 HP, 20% armor, 3-6 damage)
  • Up KRF Sworn Sworn Blades (3 Stars): Sworn Blades have the most health and wield dual weapons. (110 HP, 30% armor, 6-10 damage)
  • Up KRF Recurve Recurve Bow (4 Stars): Gives reinforcements a ranged weapon that can target ground and flying enemies. (110 HP, 30% armor, 6-10 damage, 16-30 ranged damage)

Kingdom Rush: Origins

Archer Tower

  • KRO Upgrade A 01 Level-1 Master Shooter (1 star): Increases Archer attack damage.
  • KRO Upgrade A 02 Level-2 Treesinged Bow (1 star): Increases Archer attack range (by 10%).
  • KRO Upgrade A 03 Level-3 Obsidian Heads (2 stars): Archers deal maximum damage against unarmored targets.
  • KRO Upgrade A 04 Level-4 Elven Training (2 stars): Improves all Archer special abilities.
  • KRO Upgrade A 05 Level-5 Bloodletting Shot (3 stars): Archer attacks have a 15% chance of causing heavy bleeding.
Tower Damage
Hunter Arbor 22
Watcher Arbor 22
Sentinel Arbor 44
Arcane Archers 44
Golden Longbows Long-range shot: 132
Long-range shot combined with a "crit": 242
Short-range shot: 66
Short-range shot combined with a "crit": 154


  • KRO Upgrade B 01 Level-1 Elven Fencing (1 star): Reduces basic barracks construction costs. (-10% for level 1-3 Barracks)
  • KRO Upgrade B 02 Level-2 Expert Tactician (1 star): Increases barracks rally point range. (by 20%)
  • KRO Upgrade B 03 Level-3 Enchanted Armor (2 stars): Barracks equip soldiers with improved armor. (+10%)
  • KRO Upgrade B 04 Level-4 Moon Forged Blades (2 stars): Soldier attacks deal 15% additional magic damage.
Tower Damage without Upgrade (with Upgrade)
Defender Barracks 1-4 (3-5)
Warden Barracks 3-7 (5-9)
Ranger Barracks 8-12 (11-14)
Bladesinger Hall 11-14 (14-18)
Forest Keepers 24-36 (30-42)
  • KRO Upgrade B 05 Level-5 Blessing of Elynie (3 stars): Soldiers have a 10% chance of cheating death when dealt lethal damage. (Soldiers revive with full health when proced.)

Magic Tower

  • KRO Upgrade M 01 Level-1 Crystal Focus (1 star): Increases Mage attack range. (+5%)
  • KRO Upgrade M 02 Level-2 Empowered Magic (1 star): Increases Mage attack damage. (+17.5%)
  • KRO Upgrade M 03 Level-3 Crystal Gazing (2 stars): Increases Mage attack range (+5% from crystal focus)
  • KRO Upgrade M 04 Level-4 Unstable Magic (2 stars): Mage attacks have a small chance (5%) of dealing triple damage. (It is shown as a "BLAST!".)
  • KRO Upgrade M 05 Level-5 Alter Reality (3 stars): Mage attacks have a chance of teleporting enemies back down the path.

Druid Tower

  • KRO Upgrade D 01 Level-1 Hardened Boulders (1 star): Increases Druid attack damage. (+10%)
  • KRO Upgrade D 02 Level-2 Sharp Splinters (1 star): Increases boulder explosion area.
  • KRO Upgrade D 03 Level-3 Earth Mastery (2 stars): Increases Druid attack range. (by 10%)
  • KRO Upgrade D 04 Level-4 Heavy Load (3 stars): Boulder explosions ignore physical armor.
  • KRO Upgrade D 05 Level-5 Shocking Impact (3 stars): Boulder explosions slow enemies for a short time.


  • KRO Upgrade Th 01 Level-1 Thunderbolt (2 stars): Adds 3 additional thunderbolts.
  • KRO Upgrade Th 02 Level-2 Roaring Gale (2 stars): Increases thunderbolt damage and reduces cooldown by 10 seconds.
  • KRO Upgrade Th 03 Level-3 Thunderstorm (3 stars): Adds 2 additional thunderbolts, while heavy winds slow down all enemies.
  • KRO Upgrade Th 04 Level-4 Monsoon (3 stars): Increases thunderbolt damage and doubles wind slowing effect.
  • KRO Upgrade Th 05 Level-5 Furious Tempest (3 stars): Increases thunderbolt damage and casts additional bolts at random enemies.


  • KRO Upgrade R 01 Level-1 Skilled Defenders (2 stars): Skilled defenders have more health and better equipment. (60 HP, 3-5 damage, 20% armor)
  • KRO Upgrade R 02 Level-2 Elven Stars (3 stars): Gives reinforcements a ranged weapon that can target ground and flying enemies. (60 HP, 20% armor, 3-5 damage, 7-10 ranged damage)
  • KRO Upgrade R 03 Level-3 Green Wardens (3 stars): Green Wardens have more health, better armor and improved weapons. (100 HP, 35% armor, 5-10 damage, 10-20 ranged damage)
  • KRO Upgrade R 04 Level-4 Rapid Response (3 stars): Reduces reinforcements cooldown by 5 seconds. (From 15 seconds to 10 seconds.)
  • KRO Upgrade R 05 Level-5 Moon Sentinels (4 stars): Moon sentinels are elite elven huntresses, riding giant panthers. (150 HP, 50% armor, 10-15 damage, 20-30 ranged damage)

Kingdom Rush: Vengeance


Upgrades in Kingdom Rush: Vengeance are bought with Souls instead of Stars and are gained differently to previous games.

  • Completing a Campaign level awards a certain number of souls upon completion.
  • There are exactly as many souls rewarded throughout the main Campaign as there are required to fill all upgrade slots.


  • KRVUp Blitz BLITZ TACTICS (1 soul): Increases the bonus gold for calling an early wave. (80% additional gold)
    • KRVUp Rations WAR RATIONS (1 soul): With a full belly, Barracks units have improved health. (30% additional HP)
    • KRVUp GXR1 GXR-1 TARGETING SYSTEM (2 souls): Improved with Goblin technology, Archery towers gain extra range. (5% additional range)
    • KRVUp Bombs BIGGER BOMBS (1 soul): Infused with powerful alchemy, explosions now have a bigger range of effect. (20% additional area of effect)
    • KRVUp Runes RUNES OF POWER (2 souls): All mage towers have a slight chance of dealing double damage on each attack. (10% chance of double damage)
  • KRVUp Guild GUILD OF MERCHANTS (2 souls): Costs of towers' special skills is now reduced. (15% cost reduction)
    • KRVUp Master MASTER ARCHITECTS (2 souls):All towers gain extra bonus damage. (10% additional basic attack damage)
    • KRVUp Coils DEATHRAY COILS (4 souls): Replace the flags on each exit with deadly tesla coils that zap incoming enemies. These coils can zap enemies every 180 seconds for 150-300 true damage.


  • KRVUp Backto BACK TO BATTLE (1 soul): Reduces the respawn time of Heroes. (10% respawn reduction)
  • KRVUp Special SPECIAL TRAINING (1 soul): Thanks to a secret and intense training heroes level up faster. (25% extra XP gain)
    • KRVUp Oneman ONE MAN ARMY (2 souls): All heroes improve their base attack damage. (15% extra damage)
  • KRVUp Ultimate ULTIMATE POWER (1 soul): All heroes' Ultimate skills now have their cool downs reduced. (20% CD reduction)
    • KRVUp Will IRON WILL (2 souls): All heroes improve their maximum health. (20% HP increase)
  • KRVUp Shield SHIELD OF PROTECTION (2 souls): Every basic attack inflicted to a hero has a small chance of dealing no damage. (10% chance to trigger)
  • KRVUp SWind SECOND WIND (4 souls): Heroes now have a small chance of instantly respawning. (10% chance to trigger)

Demon Goonies

  • KRVUp Infernal INFERNAL COMBUSTION (1 soul): After dying, Goonies explode dealing area damage to all affected enemies.
  • KRVUp Trained TRAINED GOONIES (2 souls): Better trained for combat, Goonies now have improved health and damage.
  • KRVUp Guards DEMON GUARDS (3 souls): Goonies are now Demon Guards! They are capable of withstanding huge amounts of damage.
    • KRVUp Nova INFERNAL NOVA (2 souls): Demon Guards now die with a bigger explosion. Deals extra damage and reaches more enemies.
  • KRVUp Hellion HELLION TRIDENTS (3 souls): Goonies are now Hellon Tridents! They are demons that can hit their enemies with a ranged attack.
    • KRVUp Tridents FLAMING TRIDENTS (2 souls): Hellion Tridents now throw burning tridents that burn enemies on impact for a brief duration.
  • KRVUp PitLord PIT LORD (6 souls): When reinforcements are called to the battlefield, now there's a small chance of summoning a Pit Lord with them.

This Upgrade tree allows either Demon Guards or Hellion Tridents but not both.

Soul Impact

  • KRVUp XImpact EXTRA IMPACTS (2 souls): When the spells cast, adds an extra impact near the place the first one hit.
    • KRVUp SShock SOUL SHOCKWAVE (1 soul): The impact now stuns the affected enemies for a brief duration.
  • KRVUp Call CALL OF THE DAMNED (3 souls): After the impact, releases a bunch of spectres that chase and deal damage to enemies.
    • KRVUp XSpect EXTRA SPECTRES (2 souls): Soul impacts now release additional spectres when they hit
    • KRVUp Fear FEAR OF THE DAMNED (1 soul): Enemies hit by the spectres decrease their movement speed for a few seconds.
  • KRVUp Feast FEAST OF THE DAMNED (1 soul): Each enemy killed by this spell reduces the cool down for the next cast.
  • KRVUp Echoes SOUL ECHOES (3 souls): After the impact ends, there is a small chance of it striking again in the same place.
  • KRVUp Tornado TORNADO OF SOULS (5 souls): When the spell is cast, extra impacts will fall across the battlefield.

See Also

Upgrade Strategy