Gold is the player's primary resource in Kingdom Rush.
Every stage gives the player a predetermined amount of gold to spend on towers and upgrades. Heroic and Iron Challenge stages usually give more gold in the beginning. Every enemy gives different amount of gold usually depends on their strength and their HP.
All enemies killed will give gold. Exceptions to this rule are:
- Skeletons, Skeleton Knights and Fallen summoned by Necromancers and Sand Wraiths.
- Spiderlings spawned by Spider Matriarchs (only Flash) , Noxious Creepers and Jungle Matriarchs.
- Saurians summoned by Saurian Savants.
- Savage Zombies raised by Blood Tricksters.
- Husks and Swamp Things spawned from the Poison Pools in Rotten Forest and Fungal Forest.
- Polymorphed enemies clicked to death.
- Demon Legions that are duplicated instead of spawned from entrances.
- Fallen spawns after Immortal's death and entrances.
- Parasytes and Reapers spawning from eggs and soldiers in Lost Jungle and Temple of Saqra. Those spawning from entrances still give gold.
- Werewolves spawned from soldiers attacked by Lycans.
- Zombies and Ghouls spawned by Jack'O Lantern (except Steam and Android)
- Duplicated Gloomies.
- Cutthroats summoned by Hoplites.
- No extra gold from the resulting value of Fungus Breeder's abilities.
- Enemies summoned by Zealots.
- Cloud Stalkers spawned from troops by other Cloud Stalkers.
- Drider spawned from troops.
- Shadowspawn that come from troops.
- Enemies that was tapped enough from Mine Train to be destroyed. However, if the player allowed enemies to spawn from Mine Carts, it will give gold.
- Apex Shards summoned by Ice Witches.
- Draugr raised by Valkyries.
- Baa Sans summoned by Joe Jenkins.
- Elven Rangers spawned by Alleria Swiftwind.
- Alleria Swiftwind herself in Silveroak Outpost.
- Troops polymorphed into Sheep by High Sorcerers (Enemies polymorphed into friendly sheep by a possessed High Sorcerer or possessed enemies polymorphed into Sheep by an enemy High Sorcerer will give gold)
- Footmen spawned by War Wagons.
In Kingdom Rush: Vengeance, Machine Enemies like Chomp Bots and MechaDwarf MK.9s will only give gold when their disabled bodies break apart. Recruits promoted to Footmen by Troop Captains will give the same amount of gold as a Recruit.
In the Shop on the mobile version, a bag of gold can be bought for 850 gems (Kingdom Rush/Frontiers). When used, it gives 500 pieces of gold for the current stage. In Origins the shop offers the Hand of Midas for 750 gems that doubles the player´s gold income for a while.
The Premium Content gives a 30% bonus to starting gold if enabled. Captain Blackthorne has an ability to boost the gold bounty of enemies killed near him. Assassins with pickpocket ability upgraded has a small chance to steal gold from their enemies.