This is my official Appeal for this turn, against the Keyword "Immutable X".
Immutable X: This card is immune to non-combat effects (that is, it doesn't prevent damage dealt in regular combat) from cards costing X Rads or less. It can still be targeted, but the effect will not occur, nor will any follow-up effects that depended on it. Immutable applies in all zones (deck, hand, discard, board, maybe others), to all cards (in the given price bracket). A card with X in the cost is treated as whatever was paid for it by Immutable.
The ability is too broad reaching. It completely invalidates large swathes of a potential deck. The fact that 0-cost Generic cards that destroy 1-Rad stickies or deal 30 direct damage exist suggests that we can expect low-cost cards to be able to apply effects to high-cost ones in general. Immutable is literally called out in the definition for Steel colour cards, however there is no colour based drawback so the bonus would naturally not be as strong. Additionally, Magic the Gathering has long ruled for Keywords like Hexproof, Shroud and Protection that an effect is only resisted if it "targets" the card/player. Thus I propose the definition is altered to (change emhasised):
Immutable X: This card is immune to non-combat effects (that is, it doesn't prevent damage dealt in regular combat) from cards targeting it that costing X Rads or less. It can still be targeted, but the effect will not occur, nor will any follow-up effects that depended on it. Immutable applies in all zones (deck, hand, discard, board, maybe others), to all cards (in the given price bracket). A card with X in the cost is treated as whatever was paid for it by Immutable.
This would mean Cards like Modest Demolition or Dies to Removal that effect a specific, targeted card would still have to meet the requirements of Immutable, but cards like Polluted Wasteland which trigger on each/any Card rather than a specific target, would not be prevented. Each/any cards, by definition, have broader reach and thus would have a lesser effect than a Target card for the same cost. I feel this still meets the spirit of the Keyword without neutering it.