The revelation that Halo 5: Guardians will feature microtransactions has caused enough of a stir that 343 Industries stepped in with a blog post explaining what they buy and why they're there.

First, the transactions. A currency called REQ Points will be earned after multiplayer matches in the games Arena or Warzone modes. These buy REQ Packs, which contain a variety of weapons, skins, armor and other goodies. REQ Packs also are earned for free when a player levels up.

Of course, REQ Packs may be purchased for real cash, "as a matter of convenience," notes development chief Josh Holmes. He emphasized that REQ Points can only buy cosmetic items in the game's Arena mode.

In Warzone, where weapons acquired via REQ Packs may be used, Holmes says a balancing system is in place to make sure they can't be abused by pay-to-win players.

First, Warzone matches will be assigned a REQ Level governing the level of items that may be brought into the game. Second, "energy points" are needed to bring those weapons into a game, and players acquire those through their individual and team performance in the match.

"The REQ System is designed to generously reward players with a steady stream of content to keep gameplay fresh," Holems said. "We'll be continuing to release new REQ content, post launch, so there are always new toys to play with. All REQ content in the game can be earned through the regular course of play in multiplayer."

Holmes also noted that "a portion of the proceeds" from the real-money sale of REQ points go toward prize pools offered in the Halo Championship Series.