Stars and gems

Gems drop from enemies during every battle, are kept after a win or a loss, and buy the items of the shop.

Campaign stars

A Campaign battle starts with 20 lives, and a win gives 3 stars with 18 or more lives left (a Heartbox can raise lives above 20), 2 stars with 6 to 17, and 1 star with fewer. A stage keeps its best Campaign result, and 3 stars open its two challenges.

Stars per win

Stars per win
Win	Stars
Campaign, 18 or more lives left	3
Campaign, 6-17 lives left	2
Campaign, 1-5 lives left	1
Heroic Challenge	1
Iron Challenge	1

Gems

Carried by enemies on every stage

Every wave is made of one or more groups of enemies, and one enemy of each group carries gems; they are added only when that enemy is killed. Each stage has a base gem value, from 100 on stage 1 to 500; a mode gives 80% of it in Campaign and 48% in each challenge, split evenly (rounded down) among all the groups of the stage's waves, and each carrier holds 20% less or 20% more than its share at random, rounded down. In Campaign the carrier is a random enemy of the group and the pick can fall on a part of the group that sends no enemy, so killing every carrier gives a number of gems between the two figures below; in the challenges it is the group's last enemy, and a group whose last part sends no enemy has no carrier. Killing every carrier of a Campaign play gives between 56 and 468 gems depending on the stage.

Stage	Groups	Gems per carrier	All carriers killed
1. Southport	7	8 or 13	56-91
2. The Outskirts	7	13 or 20	91-140
3. Pagras	19	6 or 9	114-171
4. Twin River Pass	26	5 or 8	130-208
5. Silveroak Forest	27	5 or 8	125-216
6. The Citadel	39	4 or 7	148-273
7. Coldstep Mines	30	6 or 9	180-270
8. Icewind Pass	30	6 or 9	180-270
9. Stormcloud Temple	34	7 or 10	238-340
10. The Wastes	31	8 or 12	248-372
11. Forsaken Valley	36	6 or 9	216-324
12. The Dark Tower	28	11 or 16	308-448

13. Sarelgaz's Lair	56	5 or 8	260-448
14. Ruins Of Acaroth	48	6 or 9	240-432
15. Rotten Forest	39	8 or 12	296-468
16. Hushwood	34	8 or 13	200-442
17. Bandit's Lair	42	7 or 10	210-420
18. Glacial Heights	37	8 or 12	192-444
19. Ha'Kraj Plateau	39	8 or 12	288-468
20. Pit Of Fire	30	10 or 15	270-450
21. Pandaemonium	54	5 or 8	145-424
22. Fungal Forest	51	5 or 8	145-408
23. Rotwick	41	7 or 10	140-410
24. Ancient Necropolis	37	8 or 12	160-444

25. Nightfang Swale	47	6 or 9	162-423
26. Castle Blackburn	47	6 or 9	120-423

Stage	Groups	Gems per carrier	All carriers killed
1. Southport	6	6 or 9	36-54
2. The Outskirts	6	9 or 14	54-84
3. Pagras	12	6 or 9	72-108
4. Twin River Pass	10	9 or 14	90-140
5. Silveroak Forest	14	6 or 9	84-126
6. The Citadel	20	5 or 8	100-160
7. Coldstep Mines	14	8 or 12	112-168
8. Icewind Pass	13	8 or 13	104-169
9. Stormcloud Temple	15	9 or 14	135-210
10. The Wastes	12	12 or 19	144-228
11. Forsaken Valley	12	12 or 19	144-228
12. The Dark Tower	12	16 or 24	192-288

13. Sarelgaz's Lair	16	12 or 18	192-288
14. Ruins Of Acaroth	16	12 or 18	192-288
15. Rotten Forest	15	12 or 19	180-285
16. Hushwood	14	13 or 20	182-280
17. Bandit's Lair	16	12 or 18	192-288
18. Glacial Heights	15	12 or 19	180-285
19. Ha'Kraj Plateau	16	12 or 18	192-288
20. Pit Of Fire	12	16 or 24	192-288
21. Pandaemonium	19	9 or 14	171-266
22. Fungal Forest	19	9 or 14	153-238
23. Rotwick	17	11 or 16	187-272
24. Ancient Necropolis	16	12 or 18	192-288

25. Nightfang Swale	18	10 or 15	180-270
26. Castle Blackburn	14	13 or 20	156-240

Stage	Groups	Gems per carrier	All carriers killed
1. Southport	1	38 or 57	38-57
2. The Outskirts	1	57 or 86	57-86
3. Pagras	2	38 or 57	76-114
4. Twin River Pass	2	48 or 72	96-144
5. Silveroak Forest	3	32 or 48	96-144
6. The Citadel	4	28 or 43	112-172
7. Coldstep Mines	3	38 or 57	114-171
8. Icewind Pass	3	38 or 57	114-171
9. Stormcloud Temple	2	76 or 115	152-230
10. The Wastes	2	76 or 115	152-230
11. Forsaken Valley	2	76 or 115	152-230
12. The Dark Tower	2	96 or 144	192-288

13. Sarelgaz's Lair	4	48 or 72	192-288
14. Ruins Of Acaroth	3	64 or 96	192-288
15. Rotten Forest	3	64 or 96	192-288
16. Hushwood	3	64 or 96	192-288
17. Bandit's Lair	4	48 or 72	192-288
18. Glacial Heights	3	64 or 96	192-288
19. Ha'Kraj Plateau	3	64 or 96	192-288
20. Pit Of Fire	2	96 or 144	192-288
21. Pandaemonium	4	48 or 72	192-288
22. Fungal Forest	5	38 or 57	152-228
23. Rotwick	4	48 or 72	192-288
24. Ancient Necropolis	3	64 or 96	192-288

25. Nightfang Swale	4	48 or 72	192-288
26. Castle Blackburn	6	32 or 48	160-240

What gems buyThe shop's items and their price

Item	Gems
Dynamite	50
Frozotov	50
Chill Wand	250
Heartbox	350
Gold Bag	850
Fat Boy	999

Each item and what it does is on the items page.