If you're not already playing Battlefield 1, you might be soon. The game's rollout has been somewhat unique, as a portion of the game is playable now, the full game will unlock tomorrow, still days ahead of its release date. To help make sense of the situation, here's an explanation of what's available and when.

The World War I shooter from Battlefield series developer DICE officially launches on October 21. However, the game's Play First Trial--which contains a limited selection of the game's single-player and multiplayer content--launched back on October 13 for EA/Origin Access subscribers.

EA Access is available on Xbox One and Origin Access is the subscription service's PC version. No version of EA Access is available on PlayStation 4. However, people who buy the $80 Early Enlister Edition of Battlefield 1 can start playing the full game tomorrow, October 18. Like the full game next week, the Early Enlister Edition unlocks at midnight. This premium version of Battlefield 1, which also comes with extra digital content, is available on PS4, Xbox One, and PC.

The ongoing Play First Trial version of Battlefield 1 contains five maps and four modes for multiplayer, along with the single-player missions Storm of Steel and Through Mud and Blood. When the Early Enlister Edition comes out tomorrow, the remaining multiplayer maps and modes will be available for Play First Trial members. However, that early access period is limited to 10 hours, so if you've reached the limit by October 18, you'll need to buy the game to play those new maps and modes.

EA/Origin Access members save 10 percent on all digital content, knocking down the base game to $54, the Early Edition Edition to $72, and the Ultimate edition to $117. The Ultimate Edition is the only version of the game to include its $50 premium pass, which comes with four expansion packs. Additionally, premium pass-owners will have access to DLC maps two weeks before people who buy it standalone, just like how it works with Star Wars Battlefront.

Battlefield 1's first DLC map is called Giant's Shadow. It's free for everyone and comes out in December. The game's first premium pass expansion, They Shall Not Pass, comes out in March 2017.

For more on Battlefield 1, check out GameSpot's review and what other critics are saying. You can also find out everything you need to know in GameSpot's roundup of Battlefield 1 news and videos.