We already know about four characters coming to Mortal Kombat X as downloadable content, and it sounds like even more may be on the way.

Series creator Ed Boon, never one to shy away from teasing things on Twitter, recently responded to a question asking about certain characters being added to the game. Specifically, he was asked whether we'll see non-playable characters from the game's story mode made accessible to players. To this, Boon responded, "[You] mean like a 'Story Pack'?"

Rain in 2011's Mortal Kombat

There are a number of characters who have been playable in previous Mortal Kombat games, like Baraka, Rain, and Sindel, who are not only present in the game's story mode, but are challengers that you'll have to fight. Despite this, they aren't playable, although a modder recently got these characters working on PC to some extent.

Boon's tease didn't make it explicitly clear that a Story Pack would be released as premium DLC, although after learning that microtransactions were available for the game's easy Fatalities, it's hard to blame anyone for making that assumption.

Still, developer NetherRealm Studios and publisher Warner Bros. aren't entirely averse to giving stuff away; the most recent patch added a free costume, something that will be the case with every patch going forward, according to a tweet from Boon.