Dominions 5 Wiki

Acid damage can inflict Rust. It has the same chance as fire. Only units with iron weapons or iron armor can be affected by Rust.

Rusty armor can be damaged if it takes a hit in combat.

Chance for Rusty armor to be damaged = damage inflicted (before armor protection, but after shield protection) * 2%.

Rusty weapons have a 25% chance of being damaged when they inflict a hit on something. Damaged weapons have their damage reduced by 2, except for blunt weapons which have their damage reduced by 1.