Irreducible Damage a Type?

Is irreducible damage considered a "type" of damage?  Forgive me for not remembering all the card names, but I know that Legacy has a card that allows him to become immue to a choosen type of damage and Visionary has a card that allows her to change the type of damage to that of her choice.  Is irreducible damage a valid type to choose for these (and other similar) cards?  Or is irreducible a modifier, like +1 or -1, rather than a type?

Irreducible is a modifier and can't be chosen with Next Evolution, Twist the Ether, or anything similar.

It's like +1. It is not a type. Types are more like descriptors, irreducible is an in-game effect.

Damage types are Melée, Fire, Sonic, etc. Irreducible is an attribute which can be applied to damage (regardless of type). It mean cards like Fortitude and Ta Moko are of no use, because they reduce damage, so if that hero gets hit with irreducible damage, it ignores their protection. This does make Omni-10 good against Plague Rat, though, if you can get out the Ablative Coating and Reactive Plating Subroutine ASAP :).

Doesn't that cause Omni to hit himself if he is infected, or is the return damage optional?

The reactive damage need not go back to the source of the damage, unlike something like Combat Stance.

Yeah, he can hit any target. So if he's Infected, he hits himself for irreducible toxic damage, and due to having the Ablative Coating (melée, projectile, toxic) and Reactive Plating Subroutine out, he then gets to deal toxic damage to a target of his choice. It's the same story when Rat deals him irreducible melée damage at the end of his (Rat's) turn. Had some fun plinking away at him that way once. Having both Innervation Rays out helps counteract the damage you'll be taking :).

That's what I get for replying without checking the cards.