Injustice 2 is closing in on its May release, so developer NetherRealm Studios is pulling back the curtain a bit on the microtransactions planned for the game. In a nutshell, they will not "pay-to-win."

A new currency called Source Crystals is being added to the game and they will be used to purchase cosmetic items, such as new skins, or levels for alternate characters on a player's account, NetherRealm said in a post on the Injustice 2 community forums. "Source Crystals offer more opportunities to customize your fighters that won’t affect gameplay or game progression," community admin GypsyWB said. "The cosmetic adjustments to your characters are for you own personal preference of how you want your fighters to look, and can add details to your characters overall appearance."

The developer had previously revealed that new heroes can be created through various skins, and now we know that Source Crystals will be the way to do it. "Premiere Skins will change your character’s look from top to bottom. For example, you can change Supergirl into Powergirl, but the power and stats of the character are still based on Gear equipment that you’ve earned through playing the game. The Premiere Skin change is only visual."

In addition Source Crystals can be used to save time. While some skins can be unlocked through gameplay, players can buy them instead. As for the levels, once a main character on the account hits level 20, "you can use Source Crystals to level up other characters to 20."

Source Crystals will be available for purchase on the Xbox and PlayStation Stores, although exactly how much they will cost in real-world dollars hasn't been revealed.

Injustice 2 is scheduled to come out on May 16 for PlayStation 4 and Xbox One. It has been unveiling new heroes each week, with Firestorm being the most recent addition.