Iron Soul Dungeon Runes: All 4 Effects and Where to Get Them

Runes attach elemental on-hit effects to your gear. Each one lists an armour effectiveness split — how much of the rune's power applies from the helmet slot versus the body slot — so the same rune is worth different amounts depending on where you socket it.

RuneEffectArmour effectivenessWhere to get it
Frost Rune Chance to apply Frost when hit. Frost slows the enemy for a short duration, then deals bonus damage when the effect ends. Chance, duration, and final damage vary depending on rune level. Armor Effectiveness: 40% Helmet / 60% Body Cave of Runes • Grocery (~$3k, varies by level) • Season Battle Pass
Burn Rune Chance to apply Burn when hit. Burn deals damage over time for a short duration. Chance, duration, and burn damage vary depending on rune level. Armor Effectiveness: 40% Helmet / 60% Body Cave of Runes • Grocery (~$3k, varies by level) • Season Battle Pass
Corrode Rune Chance to deal bonus damage when hit. Corrode weakens the enemy, causing them to take increased damage for a short duration. Chance, bonus damage, duration, and damage increase vary depending on rune level. Armor Effectiveness: 40% Helmet / 60% Body Cave of Runes • Grocery (~$3k, varies by level) • Season Battle Pass
Methysis Rune Chance to apply Poison when hit. Poison deals damage over time at fixed intervals for a short duration. Chance, duration, tick rate, and poison damage vary depending on rune level. Armor Effectiveness: 40% Helmet / 60% Body Cave of Runes • Grocery (~$3k, varies by level) • Season Battle Pass

Which rune to run

Every rune is viable through the mid game — the Frozen Valley progression notes say exactly that, while singling out Corrode at tier 3 as the one worth considering when you get there. Lv.3 Frost, Corrode and Methysis runes all appear in the Grocery rotation at 3,000 gold, which is usually cheaper than farming the Cave of Runes for them.

Rune data transcribed from the official wiki: