The biggest change nobody’s guide mentions
Search for Warframe damage types and most results still describe Ferrite Armor, Alloy Armor, Cloned Flesh and Robotic health. That is Damage 2.0, and it no longer exists.
Damage 3.0 collapsed every health, armour and shield type into one of each, then moved vulnerabilities off health types and onto factions. All Grineer are now weak to Impact and Corrosive at all times, armoured or not. There are no resistances left to avoid.
This removes an entire category of decision. You no longer ask “what should I not use here”. You ask only “which of the two weaknesses is more useful on this faction”, which is a much smaller question and much easier to answer correctly.
Faction weaknesses
| Faction | Weak to |
|---|---|
| Grineer | Impact, Corrosive |
| Corpus | Puncture, Magnetic |
| Infested | Slash, Heat |
The remaining factions — Sentient, Murmur, Kuva Grineer, Corpus Amalgam, Deimos Infested — have their own pairs, visible in the Codex after scanning one enemy of that faction, or by aiming at an enemy with the Synthesis Scanner and the Data-Parse widget. Their unlock conditions differ: Sentient needs The Second Dream, Murmur needs Whispers in the Walls, Kuva Grineer needs The War Within, Corpus Amalgam needs the Jupiter Junction, Deimos Infested needs Heart of Deimos.
Two weaknesses per faction, one physical and one elemental, is the whole system. Everything else is status effects.
Why armour is a formula problem, not a damage problem
Enemies do not use the player armour formula. Below 2,700 net armour, enemy damage reduction is:
DR = 90% × √(armour / 2700)
That square root is the reason the Steel Path feels impossible. Plug in values:
| Net armour | Damage reduction | Effective health multiplier |
|---|---|---|
| 300 | 30.0% | 1.43× |
| 675 | 45.0% | 1.82× |
| 1,200 | 60.0% | 2.50× |
| 2,700 | 90.0% | 10.0× |
At 2,700 armour a target has ten times its listed health. Combine that with the Steel Path’s 250 percent health modifier and an enemy that reads 10,000 health actually takes 250,000 damage worth of work.
Now apply Corrosive at 5 stacks, which removes 77.8 percent of that armour and leaves 599:
DR = 90% × √(599/2700) = 90% × 0.471 = 42.4%
Effective health drops from 10× to 1.74×. Stripping armour is not a damage bonus, it is a five-fold reduction in the work required. That is why Corrosive is not optional on armoured content.
Corrosive caps at six stacks, not ten
Each Corrosive stack multiplies remaining armour by 0.74. The tooltip says ten stacks and 80 percent reduction, which reads as “stack to ten”. The arithmetic says otherwise.
| Stacks | Remaining armour | Reduction |
|---|---|---|
| 1 | 74.0% | 26.0% |
| 3 | 40.5% | 59.5% |
| 5 | 22.2% | 77.8% |
| 6 | 16.4% | 83.6% — capped at 80% |
| 10 | 4.9% | capped at 80% |
The sixth stack already overshoots the 80 percent cap. Stacks seven through ten add nothing at all. So “stack Corrosive to ten” is not a strategy, it is four wasted applications — and against trash mobs that die in one or two hits, you will never get there anyway.
Status effects, with real numbers
Physical:
| Type | Effect |
|---|---|
| Impact | Flinch plus longer stagger per stack; raises the Parazon finisher health threshold by 8% per stack, up to 80% at 5 stacks |
| Puncture | Target deals 40% less damage and takes +5% crit chance for 6s; up to 80% and 25% at 5 stacks |
| Slash | 35% of base damage per second as Cinematic damage for 6s, after a 1s delay, bypassing armour. Uncapped stacks |
Base elemental:
| Type | Effect |
|---|---|
| Heat | 50% base damage per second for 6s, panic for 4s, strips up to 50% armour over 2s. Uncapped |
| Cold | -50% move, fire and attack speed, +0.1 crit multiplier for 6s. 10 stacks reach 90% slow and +0.5 multiplier; the 10th stack freezes for 3s and adds +1.0 multiplier |
| Electricity | 50% base damage per second to enemies within 3m for 6s, stuns the target 3s |
| Toxin | 50% base damage per second for 6s, bypasses shields. Uncapped |
Combined:
| Type | Effect |
|---|---|
| Viral | +100% damage to health for 6s, up to +325% at 10 stacks |
| Corrosive | -26% current armour for 8s, multiplying, capped at -80% |
| Magnetic | +100% damage to shields and Overguard, up to +325%; blocks natural shield regen |
| Gas | 3m cloud dealing 50% base damage per second for 6s, up to 10 stacks and 6m radius, persists after the enemy dies |
| Radiation | Target attacks allies with +100% damage, up to +550%; bosses take +250% from other units at 4 stacks |
| Blast | 30% base damage explosion after 1.5s; at 10 stacks or on death, all stacks detonate for 300% base damage in 5m |
Viral versus Corrosive, settled with arithmetic
Viral’s first stack gives +100%, which is a doubling. Stacks two through ten add the remaining 225 points, so the first stack carries 30.8 percent of the total benefit and costs one application.
Corrosive’s first stack removes 26 percent of armour. Against a 2,700-armour target that moves DR from 90 percent to 83.9 percent, dropping effective health from 10× to 6.2×. That single stack does more work than nine stacks of almost anything else.
They are not competitors. Corrosive fixes the armour problem; Viral multiplies what gets through. A build with neither is doing raw damage against a 10× multiplier. A build with both needs the armour stripped first or Viral is amplifying a number that is being cut by 90 percent.
The practical split: Corrosive against armoured Grineer, Magnetic or Toxin against Corpus (Toxin bypasses the shield entirely, which is often faster than breaking it), Heat or Gas against Infested crowds.
Slash, and why the bleed is the real weapon
Slash’s bleed is 35 percent of base damage per second for six seconds, applied as Cinematic damage, which bypasses armour reduction entirely. That is 210 percent of base damage per proc, and stacks are uncapped.
A weapon with 70 percent Slash weighting and a high fire rate therefore applies a damage-over-time that ignores the 90 percent armour wall while also hitting with the direct damage. This is why “Slash and Viral” became the default answer: Viral multiplies the health damage, Slash reaches health without caring about armour, and neither depends on stripping anything first.
The catch is that Slash weighting is fixed by the weapon. Check the base physical split before assuming a weapon is a Slash weapon — the best weapons page ranks weapons with their base distributions visible.
Building the element
Elements combine in mod slot order, left to right, so mod placement decides the result. Heat plus Toxin makes Gas; Toxin plus Heat also makes Gas, but the placement changes which element is treated as first for other combinations.
Capacities and drain interact with this, and the mods guide covers the polarity math that decides whether you can fit the combination at all. If you are fighting armoured content, the Steel Path guide explains the 250 percent health modifier that makes the armour formula bite, and arbitrations is where enemies start at level 60-80 with the same formula applying.