What are the most effective damage types against enemy factions?

Solution 1:

There isn't one. Elemental damage is basically a more complicated version of rock-paper-scissors. This means that the strongest elements against a particular type of enemy will be weak against others.

There are primary elements and secondary elements, which are combinations of two primaries. The secondary elements have more pronounced rock-paper-scissors effects.

There are also physical damage types, which don't combine.

Each element and physical damage has an effect (often called a proc) - for instance Heat can set the target on fire, Cold can slow them down, Impact can knock them over. The status chance of a weapon is the probability this effect will happen. For some enemies the effect is more useful than the base damage.

Mods applied to a weapon are combined left to right and top down, with the weapon's inherent damage type applied last. The first two primaries will combine, a third primary will apply after that and a fourth primary will combine with the third to create two secondary effects.

However, lots of different elements can weaken a weapon, as they split the status chance. A 25% status chance weapon with 2 elemental damage types will roll for the ¼ change of having an effect, and then roll again for which of the elements to apply (with the relative damage as the probability).

Physical effects are in this pool too, so pure elemental weapons with high status chances can be extremely effective with the right mods as they don't dilute the effect pool.

Some weapons have guaranteed status effects that always applies. For instance the Lenz always has a Cold slow down effect, regardless of how you mod it.

You want your weapons to be complementary, rather than stacked - if your primary mows shields you want your secondary or melee to strip armour.

• The most consistent all-rounder is probably Viral (Cold + Toxin), but it takes a big hit against Infested (a Toxic Ancient can immunise all of them) and some Grineer. The hardest to use consistently is probably Radiation (Heat + Electric), but it's also the best against the highly armoured Grineer variants.

• Corpus use shields, so bring Magnetic (Cold + Electric) to strip shields or Toxin as it bypasses shields with a damage over time. They're resistant to Corrosive. They're also resistant to Gas, but it has a secondary Toxin effect that bypasses shields - if you have a very high status change Gas becomes very powerful. Impact does the most physical damage to their shields.

• Grineer use two kinds of armour, bring Corrosive (Toxin + Electric) for most and Radiation (Heat + Electric) for the Elites/bosses. They're resistant to Gas and Magnetic. Puncture does the most physical damage to their armour.

• Infested are fleshy, so most are very vulnerable to Heat or Gas (Heat + Toxin). Higher level ones (Ancient/Mutalist) aren't though, you'll need Corrosive for them. They're resistant to Toxin and Viral. Slash does the most physical damage to their flesh.

• Corrupted enemies are a mix of all of the above, bring a mix of weapons and abilities.

If you can rely on the effects happening (high status chance) these change slightly, for instance Slash becomes more universally powerful because its bleed over time effect will hurt everything.

As a general rule:

• Corpus - take Magnetic + Impact or Gas if you have a high status chance.
• Grineer - take Corrosive + Puncture, don't take Magnetic.
• Infested - take Heat/Gas + Slash, don't take Toxin.