Game modes

The Heroic Challenge and the Iron Challenge of a stage both open once that stage has 3 stars in Campaign; the level-select screen says "Complete this stage with 3 stars to unlock this mode."

Stars from every mode

Each mode's win is kept on its own: up to 3 stars from Campaign and 1 from each challenge, 5 per stage and 130 over the 26 stages.

Campaign

20 lives, 7-20 waves, 1-3 stars.

Heroic Challenge

1 life, 6 waves, 1 star.

Iron Challenge

1 life, 1 wave, 1 star.

Campaign is the story mode: 20 lives and 7 to 20 waves depending on the stage. A win gives 3 stars with 18 or more lives left, 2 stars with 6 to 17 and 1 star with fewer. Winning a stage in Campaign opens the next stage of its chain, and winning stage 12 opens the first stage of every later chain (see All stages). The bosses appear only in Campaign.

Heroic Challenge: 1 life and 6 waves on every stage, with its own enemies and starting gold. Heroes are not allowed on stages 1-9, and the Upgrades room upgrades only count up to a level set for each stage: level 1 on stage 1, level 2 on stages 2-4, level 3 on stages 5-7, level 4 on stages 8-10 and level 5 on stages 11-26. On stages 1-9 some tower upgrades stay locked; each stage page lists them. A win adds 1 star.

Heroic Challenge in the game

"Test your tactical skills against an elite enemy force in this challenge meant for only the most heroic defenders!"

Heroic Challenge by stage

Heroic Challenge by stage
Stage	Gold	Heroes	Upgrades
1. Southport	170	No	Up to 1
2. The Outskirts	250	No	Up to 2
3. Pagras	310	No	Up to 2
4. Twin River Pass	600	No	Up to 2
5. Silveroak Forest	1,000	No	Up to 3
6. The Citadel	1,200	No	Up to 3
7. Coldstep Mines	1,000	No	Up to 3
8. Icewind Pass	1,100	No	Up to 4
9. Stormcloud Temple	2,000	No	Up to 4
10. The Wastes	1,800	Yes	Up to 4
11. Forsaken Valley	2,100	Yes	Up to 5
12. The Dark Tower	1,600	Yes	Up to 5

13. Sarelgaz's Lair	1,400	Yes	Up to 5
14. Ruins Of Acaroth	2,000	Yes	Up to 5
15. Rotten Forest	1,000	Yes	Up to 5
16. Hushwood	1,250	Yes	Up to 5
17. Bandit's Lair	1,500	Yes	Up to 5
18. Glacial Heights	1,500	Yes	Up to 5
19. Ha'Kraj Plateau	1,900	Yes	Up to 5
20. Pit Of Fire	1,900	Yes	Up to 5
21. Pandaemonium	2,200	Yes	Up to 5
22. Fungal Forest	1,700	Yes	Up to 5
23. Rotwick	1,450	Yes	Up to 5
24. Ancient Necropolis	1,100	Yes	Up to 5

25. Nightfang Swale	1,500	Yes	Up to 5
26. Castle Blackburn	1,100	Yes	Up to 5

Iron Challenge: 1 life and 1 wave on every stage, with its own enemies and starting gold. Heroes are not allowed on stages 1-9, and the Upgrades room upgrades only count up to a level set for each stage: level 1 on stage 1, level 2 on stages 2-4, level 3 on stages 5-7, level 4 on stages 8-10 and level 5 on stages 11-26. On stages 1-8 some tower upgrades stay locked; each stage page lists them. Each stage also allows only some tower lines, listed below. A win adds 1 star.

Iron Challenge in the game

"A test for the ultimate defender, the iron challenge will take your tactical skills to the limit."

Iron Challenge rules by stage

Iron Challenge rules by stage
Stage	Towers allowed	Heroes	Upgrades
1. Southport	Barracks, Artillery	No	Up to 1
2. The Outskirts	Archer Towers, Mage Towers, Artillery	No	Up to 2
3. Pagras	Archer Towers, Barracks, Mage Towers	No	Up to 2
4. Twin River Pass	Archer Towers, Barracks	No	Up to 2
5. Silveroak Forest	Archer Towers, Mage Towers, Artillery	No	Up to 3
6. The Citadel	Barracks	No	Up to 3
7. Coldstep Mines	Archer Towers, Mage Towers	No	Up to 3
8. Icewind Pass	Barracks, Artillery	No	Up to 4
9. Stormcloud Temple	Mage Towers	No	Up to 4
10. The Wastes	Archer Towers, Barracks, Mage Towers	Yes	Up to 4
11. Forsaken Valley	Barracks, Mage Towers	Yes	Up to 5
12. The Dark Tower	Archer Towers, Barracks, Mage Towers	Yes	Up to 5

13. Sarelgaz's Lair	Archer Towers, Barracks	Yes	Up to 5
14. Ruins Of Acaroth	Mage Towers, Artillery	Yes	Up to 5
15. Rotten Forest	Barracks, Mage Towers	Yes	Up to 5
16. Hushwood	Barracks, Artillery	Yes	Up to 5
17. Bandit's Lair	Archer Towers, Barracks	Yes	Up to 5
18. Glacial Heights	Barracks, Artillery	Yes	Up to 5
19. Ha'Kraj Plateau	Archer Towers, Artillery	Yes	Up to 5
20. Pit Of Fire	Archer Towers, Barracks, Artillery	Yes	Up to 5
21. Pandaemonium	Archer Towers, Barracks, Mage Towers	Yes	Up to 5
22. Fungal Forest	Barracks, Mage Towers	Yes	Up to 5
23. Rotwick	Archer Towers, Mage Towers	Yes	Up to 5
24. Ancient Necropolis	Barracks, Artillery	Yes	Up to 5

25. Nightfang Swale	Mage Towers, Artillery	Yes	Up to 5
26. Castle Blackburn	Barracks, Mage Towers	Yes	Up to 5

Every battleCalling waves early

Calling the next wave before its timer runs out gives 1 gold for each second left on the timer, rounded to the nearest second, and, when 2 or more seconds were left, moves every spell cooldown that is running forward by the same number of seconds. Calling the first wave gives nothing. The most a wave can pay is on its stage page, under Waves.

All stages

Stars and gems

Difficulty