Mechanic: Decoy

Mechanic in idea form
One ally is used as a decoy while you or an ally is able to use the element of surprise to your advantage. This is the stereotypical rogue tactic, relying more on brains than brawn. Decoys can be used offensively, allowing someone else to land a surprise attack, or defensively, to aid in someone's escape.

Mechanic in rule form

Attack Decoy
This is an ally ability that can target an enemy hero or ally. After pressing the "Ability" button, you select your target. You then choose your hero or another ally, provided that they can attack, and press the "Attack" button. Now combat takes place, your decoy will not attack(simply distract as a decoy) but the enemy will retaliate for half damage(rounded up). The decoy will do a slide transition to the left, leaving the screen and the enemy will do the same, taking its place on the left. Your surprise attacker will slide in leftward as well, attack the enemy for double its base(value originally on the card) attack, and then combat resolves(without the enemy retaliating your surprise attacker). All involved are now exhausted.

Escape Decoy
This ally ability works similarly to Attack Decoy but is defensive. It requires both the decoy and target not be exhausted(both have to be able to run). You press the Ability button but select your hero or ally instead. The target you selected is unattackable until the beginning of your next turn; so long as the decoy remains in play. When attacked next turn(opponent's), the decoy will also take half damage(rounded up) and does not retaliate. Escape Decoy cannot target Protectors(they can't protect and escape at the same time). This limitation is for semantic and balance purposes.

Master Decoy
Simply a keyword, as a title, that grants the Attack Decoy and Escape Decoy ability. Just like how Protector is a keyword title.

Thank you for reading my proposed Decoy mechanic. As always, I welcome any comments, suggestions, or flames you have. Somewhat in that order ^^.

Examples:
Note, visit the Last Resort mechanics page for info on it.

Quote:

Originally Posted by AnAdolt

Name: Infiltration
Card Type: Rogue Ability
Casting Cost: 2
Effect: Deal 2 damage to target enemy. Reduce cost by 1 if Decoy was used this turn. Last Resort—reduce cost by 1.
Flavour Text: "Ma-xi-mum se-cur-i-ty? What's that?"

Quote:

Originally Posted by AnAdolt

Name: The Mastermind
Card Type: Rogue Ally
Casting Cost: 4
Stats: 2/4
Effect: Decoy Master. Last Resort—The Mastermind gets +1/+1 as long as you have no cards in hand.
Flavour Text: He also goes by two other names: cloak and daggers.

Quote:

Originally Posted by AnAdolt

Name: Stratagem
Card Type: Rogue Ability
Casting Cost: 1
Effect: Target ally gains Escape Decoy until your next turn. Last Resort—gain Escape Decoy permanently instead.
Flavour Text: Let shadow be your home. Until opportunity knocks on your door.

Quote:

Originally Posted by AnAdolt

Name: Blackjacker
Card Type: Rogue Ally
Casting Cost: 1
Effect: Attack Decoy.
Stats: 1/2
Flavour Text: "Hit me!"