Cast when Damage Taken Support

Cast when Damage Taken is a support gem. It causes a linked spell to trigger when the player takes a certain amount of damage.

Skill functions and interactions

Trigger gem: Like all trigger gems, Cast when Damage Taken only "casts" spells. Attack gems such as Double Strike are not considered spells. Multiple spells can be linked to a single trigger gem, and will all be triggered if so. Multiple copies of Cast when Damage Taken will also function independently.

Damage counter and cooldown: Each linked spell gains an internal damage counter that tracks the total accumulated damage taken from hits, though not from damage over time or the Blood Magic passive (e.g. you cannot use to trigger Cast when Damage Taken). All damage counters will be reset to 0 upon entering a new area. When a linked spell is cast, it is put on cooldown for 250 ms and will not track damage during that time.

Multiple copies of the same gem share cooldowns, meaning that if two copies of the same spell are triggered within 250 ms of each other, the first will trigger and the second will fail to do so as it is on cooldown. This mostly prevents using multiple copies of the same spell with Cast when Damage Taken, though the use of Cast when Damage Taken gems of different levels can avoid cooldown overlap in some circumstances due to the differing amounts of damage required to trigger the spells.

The Cast when Damage Taken gem itself does not have its own counter or cooldown.

Maximum level of supported skills: Cast when Damage Taken cannot support skills with a higher player level requirement than that of Cast when Damage Taken itself. Note that this restriction only applies to active skills; any level of other support gems may be used.

Trigger order: Trigger gems and their linked skills are cast in a certain order that depends both on which item it is equipped on and which socket the skills are in. If there are trigger gems in each equipped item, the order of operation will be:

Main hand ⇒ Amulet ⇒ Helm ⇒ Off hand ⇒ Body armour ⇒ Gloves ⇒ Boots

The linked sockets also follow a specific order, as follows:

1	⇒	2
		⇓
4	⇐	3
⇓
5	⇒	6

Damage effectiveness: The damage effectiveness increases with level, but so does the damage taken per cast; overall, the amount of damage that needs to be taken per damage effectiveness goes up at higher gem levels. The optimum is a level 2 gem, which requires 1442 damage taken per 100% damage effectiveness. In comparison, a level 20 gem requires 3057 damage taken per 100% damage effectiveness.

Targeting: Targeted spells will cast towards the enemy that caused the last damage. Reflected damage is considered to come from the enemy originally damaged. If the damage was self-caused, it will target a random enemy (if there are no enemies, it will be cast at the player, if it is a projectile, it will be fired in a random direction) .

Totems: Cast when Damage Taken can't be used with totems.

Gem level progression

Level				Damage Threshold	less/more Damage	maximum Item Level	Exp.	Total Exp.
1	38	40	27	528	70% less	38	0	0
2	40	41	29	583	66% less	40	388734	388734
3	42	43	30	661	62% less	42	477437	866171
4	44	45	31	725	58% less	44	583786	1449957
5	46	47	33	812	54% less	46	710359	2160316
6	48	49	34	897	50% less	48	1355511	3515827
7	50	51	35	1003	46% less	50	1138877	4654704
8	52	53	37	1107	42% less	52	1368233	6022937
9	54	55	38	1221	38% less	54	1638338	7661275
10	56	57	39	1354	34% less	56	1956648	9617923
11	58	58	41	1485	30% less	58	3655184	13273107
12	60	60	42	1635	26% less	60	3017327	16290434
13	62	62	43	1804	22% less	62	3576232	19866666
14	64	64	44	1980	18% less	64	4231667	24098333
15	65	65	45	2184	14% less	65	2395078	26493411
16	66	66	46	2394	10% less	66	8421063	34914474
17	67	67	46	2621	6% less	67	16159983	51074457
18	68	68	47	2874	2% less	68	41170367	92244824
19	69	69	48	3142	2% more	69	86794448	179039272
20	70	70	48	3272	6% more	70	157405063	336444335
21	72	72	50	3580	10% more	72	N/A	N/A
22	74	N/A	N/A	3950	14% more	74	N/A	N/A
23	76	N/A	N/A	4350	18% more	76	N/A	N/A
24	78	N/A	N/A	4780	22% more	78	N/A	N/A
25	80	N/A	N/A	5240	26% more	80	N/A	N/A
26	82	N/A	N/A	5730	30% more	82	N/A	N/A
27	84	N/A	N/A	6250	34% more	84	N/A	N/A
28	86	N/A	N/A	6800	38% more	86	N/A	N/A
29	88	N/A	N/A	7380	42% more	88	N/A	N/A
30	90	N/A	N/A	7990	46% more	90	N/A	N/A
31	91	N/A	N/A	8310	48% more	91	N/A	N/A
32	92	N/A	N/A	8630	50% more	92	N/A	N/A
33	93	N/A	N/A	8965	52% more	93	N/A	N/A
34	94	N/A	N/A	9300	54% more	94	N/A	N/A
35	95	N/A	N/A	9650	56% more	95	N/A	N/A
36	96	N/A	N/A	10000	58% more	96	N/A	N/A
37	97	N/A	N/A	10365	60% more	97	N/A	N/A
38	98	N/A	N/A	10730	62% more	98	N/A	N/A
39	99	N/A	N/A	11110	64% more	99	N/A	N/A
40	100	N/A	N/A	11490	66% more	100	N/A	N/A

Strategy

Due to the large amount of damage taken needed per damage effectiveness and the rapid scaling of damage taken required per level, it is advisable to use spells for purposes other than damage that do not depend heavily on the active skill level. Possible choices include:

• Frost Wall to block enemies.
• to create ground ice.
• Passive corpse disposal/minion buffing via Detonate Dead, , or .
• Lightning Warp to escape melee range. (Could backfire.)
• Curses. This can be a reliable way of automatically casting curses, at the cost of lower curse level.

Some supports also potentially combine well, especially with a persistent rapid-firing skill such as Ball Lightning:

• Passive IIR culling via , , and a skill that causes many hits.
• (As of Version 1.2.2 CWDT will only trigger Ball Lightning in this example, but Ball Lightning will then not trigger Curse On Hit.)

Quick reference chart of commonly used spell gems:

Level	Damage Threshold	Damage Modifier	Max level of spell gems	Immortal Call (Endurance charge bonus)	Molten Shell (additional armour)		Enfeeble	Frost Wall	Tempest Shield	Vortex		Phase Run	Temporal Chains	Golem (any)
1	528	-70%	38	3 (106%)	10 (156)	4	5	10	7	4	7	3	5	3
2	583	-66%	40	4 (109%)	11 (196)	5	6	11	8	5	8	4	6	4
3	661	-62%	42	5 (112%)	11 (196)	6	7	11	8	6	8	5	7	5
4	725	-58%	44	6 (115%)	12 (245)	7	7	12	9	7	9	6	7	6
5	812	-54%	46	7 (118%)	12 (245)	8	8	12	10	8	10	7	8	7
6	897	-50%	48	8 (121%)	13 (304)	9	9	13	10	9	10	8	9	8
7	1003	-46%	50	9 (124%)	13 (304)	10	10	13	11	10	11	9	10	9
8	1107	-42%	52	10 (127%)	14 (376)	11	11	14	12	11	12	10	11	10
9	1221	-38%	54	11 (130%)	14 (376)	12	12	14	12	12	12	11	12	11
10	1354	-34%	56	12 (133%)	15 (440)	13	13	15	13	13	13	12	13	12
11	1485	-30%	58	13 (136%)	16 (515)	14	14	16	14	14	14	13	14	13
12	1635	-26%	60	14 (139%)	16 (515)	15	15	16	15	15	15	14	15	14
13	1804	-22%	62	15 (142%)	17 (600)	16	16	17	16	16	16	15	16	15
14	1980	-18%	64	16 (145%)	18 (698)	17	17	18	17	17	17	16	17	16
15	2184	-14%	65	16 (145%)	18 (698)	17	17	18	17	17	17	16	17	16
16	2394	-10%	66	17 (148%)	18 (698)	18	18	18	18	18	18	17	18	17
17	2621	-6%	67	17 (148%)	19 (812)	18	18	19	18	18	18	17	18	17
18	2874	-2%	68	18 (151%)	19 (812)	19	19	19	19	19	19	18	19	18
19	3142	+2%	69	19 (154%)	19 (812)	19	19	19	19	19	19	19	19	19
20	3272	+6%	70	20 (157%)	20 (943)	20	20	20	20	20	20	20	20	20
21	3580	+10%	72	21 (160%)	21 (1040)	21	21	21	21	21	21	21	21	21
22	3950	+14%	74	22 (163%)	22 (1148)	22	22	22	22	22	22	22	22	22
23	4350	+18%	76	23 (166%)	23 (1265)	23	23	23	23	23	23	23	23	23

Cats when Damage Taken

Cats spawned by Cats when Damage Taken

Cats when Damage Taken was a trigger gem available only on April 1st 2015. It was a bug caused by a typo in source code. Like Cast when Damage Taken, it caused a linked spell to activate when the player accumulated damage taken, but besides casting the spell, it also summoned black cats. Other properties were identical to the Cast when Damage Taken skill.

Version history

Version	Changes
2.0.0	Enduring Cry is now a Warcry instead of a spell, therefore it can't be cast anymore.
1.3.1g	Fixed a bug with the trigger gems that cause spells to automatically cats on various conditions.
1.3.1	Spells triggered by Cast on Damage Taken have had their damage reduced by 25%.
1.3.0	Trigger gems are now classified as Trigger.
1.2.2	Gems may now only be supported by a single trigger gem, gems supported by multiple trigger gems will be disabled.
1.0.1	The level requirement of gems augmented by Cast on Damage Taken may not exceed the level requirement of the Cast on Damage Taken gem.
1.0.0f	Cooldown of 250ms added.
1.0.0	Cast when Damage Taken has been added to the game.