Infernal Blow

"Tracing a series of fiery runes on the length of their weapon, the caster prepares to unleash the Infernal Blow. Once imbued with fiery energy, the weapon discharges the moment it strikes any enemy. Infernal Blow burns anything struck with searing Hellfire, incinerating bone, flesh and armor. Perhaps the deadliest property of the enchantment lies in what follows a fatal hit. Any foe slain by Infernal Blow will explode in a violent conflagration, showering anything nearby with flame, igniting and killing with abandon. Masters of the Infernal Blow delight in watching enormous chain reactions of detonating victims."

— Description on the official Path of Exile website

Infernal Blow is a melee attack skill that converts half of Physical Damage to Fire Damage, applying a special debuff to enemies. If the enemy dies while affected by this debuff, they will explode, dealing fire damage to nearby enemies. Requires a Sword, Axe, Mace, Staff or Unarmed.

Skill Functions and Interactions

Damage conversion: Like all converted damage, the fire portion of Infernal Blow's damage will be modified by both fire damage increases and physical damage increases.

Duration: If the debuff caused by Infernal Blow is still active when the monster dies, it will explode even if Infernal Blow was not the killing blow. That makes this skill very effective with Melee Splash.

Explosion: The fire damage of the explosion will be 10% of the corpses' former maximum life, modified by elemental and fire damage passives and item mods. The explosion is neither an attack or a spell, so in particular it is not affected by modifiers to melee. The explosion damage cannot be reflected. Each explosion can roll a critical strike independently from the Infernal Blow attack and has a 5% base critical strike chance. While in a party, the explosion ignores the increased life added for each player beyond the first and treats the monster's life as if you were solo.

Monster Types: Magic (blue named) and rare (yellow named) monsters can be exploded, but unique monsters (orange named) cannot be.

Weapon Elemental Damage: The explosion will not be affected by increased elemental weapon damage or weapon fire damage, but the fire portion of the initial attack will be.

Gem level progression

Level			Damage Effectiveness	Attack Damage	Exp.	Total Exp.
1	12	33	104%	103.9%	0	0
2	15	39	105%	105.4%	15249	15249
3	19	48	107%	106.9%	41517	56766
4	23	56	108%	108.5%	81983	138749
5	27	64	110%	110%	147968	286717
6	31	73	112%	111.5%	250557	537274
7	35	81	113%	113.1%	405086	942360
8	38	88	115%	114.6%	447718	1390078
9	41	94	116%	116.1%	615318	2005396
10	44	100	118%	117.7%	834639	2840035
11	47	106	119%	119.2%	1570760	4410795
12	50	113	121%	120.7%	1633987	6044782
13	53	119	122%	122.3%	2151030	8195812
14	56	125	124%	123.8%	2812189	11008001
15	59	132	125%	125.3%	5099360	16107361
16	62	138	127%	126.9%	9400731	25508092
17	64	142	128%	128.4%	15273366	40781458
18	66	146	130%	129.9%	26286582	67068040
19	68	151	131%	131.5%	62890590	129958630
20	70	155	133%	133%	212046017	342004647
21	72	159	135%	134.5%	N/A	N/A
22	74	N/A	136%	136.1%	N/A	N/A
23	76	N/A	138%	137.6%	N/A	N/A
24	78	N/A	139%	139.1%	N/A	N/A
25	80	N/A	141%	140.7%	N/A	N/A
26	82	N/A	142%	142.2%	N/A	N/A
27	84	N/A	144%	143.7%	N/A	N/A
28	86	N/A	145%	145.3%	N/A	N/A
29	88	N/A	147%	146.8%	N/A	N/A
30	90	N/A	148%	148.3%	N/A	N/A
31	91	N/A	149%	149.1%	N/A	N/A
32	92	N/A	150%	149.9%	N/A	N/A
33	93	N/A	151%	150.6%	N/A	N/A
34	94	N/A	151%	151.4%	N/A	N/A
35	95	N/A	152%	152.2%	N/A	N/A
36	96	N/A	153%	152.9%	N/A	N/A
37	97	N/A	154%	153.7%	N/A	N/A
38	98	N/A	154%	154.5%	N/A	N/A
39	99	N/A	155%	155.2%	N/A	N/A
40	100	N/A	156%	156%	N/A	N/A

Version history

Version	Changes
2.1.0	Attack skills that have their damage based on the wielded weapon have their mana costs fixed in place from level 1 onwards. Radius increased by 22%.
2.0.0	Base damage increased by 4% (from 125% to 130% of base damage). Now grants 0.5% increased area of effect radius per 1% of quality (was 1% per 1% quality). The explosion effect can no longer reflect damage to the player. The explosion damage has been reduced from 25% to 10% of monsters life.
1.3.0	The mana costs of Elemental Hit, Glacial Hammer, Infernal Blow and Lightning Strike have been reduced.
1.0.0	The effect for Infernal Blow has been improved.
0.11.4	Fixed a bug where Infernal Blow could still apply to targets if the attack missed.
0.10.2	Infernal Blow's physical damage now increases by 4% per level rather than 3%.
0.10.0	Now has +25% damage effectiveness rather than +12% attack damage.
0.9.12	Now works with unarmed attacks.
0.9.11i	Fixed Infernal Blow so that it benefits from increased area of effect.
0.9.4c	Set the default critical strike chances of Infernal Blow (7%)
0.9.3g	Changed Infernal Blow to not have the damage scaled by mods that affect Spell Damage.
0.9.3c	Fixed a bug that caused damage bonuses to not appear on many weapon skills. Increased damage by raising its flat damage bonus from 10% to 12%.
0.9.3	The stats which convert damage from one type to another now calculate the damage in a way that takes into account your physical damage bonuses. Fixed a bug where Infernal Blow was able to explode an enemy several times.
0.9.2	Infernal Blow does more damage at higher levels than before.