Despite detailing Darkseid’s dreadful deeds done during Superman, Man of Steel, the dastardly dictator demanded a duplicate delivery of his dark devices come Legion of Super Heroes. The lead designer, Ben Seck, delightfully dispensed with this desire. Today’s debut discloses not only Darkseid and his diabolic demeanor, but it also describes a mechanic doubly dear to developers and designers—a mechanic that drops dudes and dudettes directly into the duel:

Needless to say, dictionary.com is my dearest friend after that paragraph-long debacle. Hopefully I can depart from my overuse of the letter “d” long enough to describe the details of substitute, the newest mechanic to descend into Vs. System (and known internally as “Darkseid’s duplicate” or alternatively, “double drop”). Substitute is pretty simple once you’ve seen it in action, but if you’re new to the mechanic here's a quick summary of how it works:

• You can put a substitute character directly into play by removing another character with equal or higher cost from the game.
• You can only use substitute during your recruit step.
• You can’t use substitute to get around character uniqueness.
• You can substitute a character over another copy of that character.

For those more technically inclined, here is the box-topper description:

Substitute characters have the following payment power:

Reveal this card >>> You may remove from the game a ready character you control with cost greater than or equal to the cost of this card. If you do, put this card into play. Use this power only if this card is in your hand and only during your recruit step.

The big detail to note that’s not directly in the above description is that substitute can’t be used to get a duplicate of a unique character you control into play; at some point during development the idea of dual Darkseids overcame R&D with terror more than delight (thus invalidating in one fell swoop both of my names for the mechanic starting with d’s). Fortunately, there are still plenty of cool things you can do with substitute, many of which will be highlighted today and in subsequent previews. Today’s preview delivers merely a peek at that design space, and reveals one of the more traditional tensions of (virtually) discarding copies of a character that you have in play. Put another way, the reward for substituting a character generally has to be better than any other use you expect to get out of keeping the card in your hand—whether it be for a power-up, to pay discard costs, or to defend against those pesky Future Foes.

In its rawest interpretation, substitute gives you a bigger window to hit a critical character. Now every “B-team” character in your deck can be substituted out by your real drop if you’re lucky enough to draw it on the subsequent turn. Dark Firestorm may not be that type of character, but he provides a lot of options to which decks don’t normally have access. Dark Firestorm’s substitute power looks easy to evaluate: if the power-up is immediately useful, keep the card in your hand. Otherwise, substitute the mockery over himself to dig deeper into the deck. This will help you hit future character drops, get a needed plot twist, or just find a power-up for someone more useful—say, Darkseid himself. But Dark Firestorm’s a little more subtle than that; since he’s also concealed, he can act as virtual recovery for a visible 3-drop character in play by hiding it in the concealed area.

It’s easy to see the raw power that can be added to characters with the addition of a short keyword. The original Big D, Dr. Doom, or even a new-age Wonderman quickly become ridiculous if granted substitute, but only time will reveal which of these characters receives the substitute treatment first. As with many mechanics, it’s just a matter of time before your personal favorite makes an appearance—again, and again, and again.

My thanks to lead designer Ben Seck for refining the substitute mechanic, and to Matt Hyra for the original idea. (Unbeknownst to most, substitute was created during the very beginning of the first Justice League of America set design. At the time, it was called transplant, and represented the various monkeys and psi-powered villains in the set who could jump from body to body. That Matt Hyra. . .) Ben Seck—dirty designs, done dirt cheap.