Upgrades

Upgrades 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.
==Stars and Upgrade Points==
===Stars===
Stars can be obtained in several ways:
* Completing a Campaign level gives stars based on the number of lives left:
** 18-20 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.
In the first three games, upgrades are bought with stars. In Kingdom Rush: Vengeance and Kingdom Rush 5: Alliance, stars are purely cosmetic indicators of a player's progress.
===Upgrade Points===
Upgrades in Kingdom Rush: Vengeance and Kingdom Rush 5: Alliance are bought with Upgrade Points. Unlike in previous games, upgrade points are exclusively earned from Campaign mode; completing Heroic and Iron Challenges give no upgrade points. The number of upgrade points earned is independent of stars; no matter how many lives the player finishes the stage with, the number of upgrade points is always the same. Most stages grant three upgrade points upon completion, with the exception of the following:
* Kazan Mines, Jokull's Nest: 4 upgrade points
* Otil Farmlands: 6 upgrade points
* Denas's Castle: 10 upgrade points
==Kingdom Rush==
===Archer Tower===
===Barracks===
===Magic Tower===
===Artillery===
===Rain of Fire===
===Reinforcements===
==Kingdom Rush: Frontiers==
===Archer Tower===
===Barracks===
===Magic Tower===
===Artillery===
===Rain of Fire===
===Reinforcements ===
==Kingdom Rush: Origins==
===Archer Tower===
===Barracks===
===Magic Tower===
===Druid Tower===
===Thunderbolt===
===Reinforcements===
==Kingdom Rush: Vengeance==
===Towers===
===Heroes===
===Demon Goonies===
===Soul Impact===
==Kingdom Rush 5: Alliance==
===Towers===
===Heroes===
===Call Reinforcements===
===Allied===
==See Also==
Upgrade Strategy
Category:Game Mechanics