Gold is the player's primary resource in Kingdom Rush.
All enemies killed will give gold. Exceptions to this rule are:
- Skeletons, Skeleton Knights and Fallens summoned by Necromancers and Sand Wraiths.
- Spiderlings spawned by Spider Matriarchs, 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.
- Rotshrooms spawned by Myconid.
- 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.
- 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.
- Units summoned by Arachnomancers.
In the Gnome 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.