AKA: THE BATTLEFIELD MEME
1. Go to Random.org's coin flipper and flip that coin.
2. Heads, you are now on one side of the conflict. Tails, you are on the other.
3. Comment with your character name, fandom, and which side you're on in your subject line.
4. Do not leave your initial comments blank. Create a scene. Set things up. Are you in a foxhole? Pinned down by enemy gunfire? Enjoying a quiet cigarette while the mecha troops of the other side are momentarily stilled? Give people something to work off of in their initial tag to you, even if it's only one or two lines.
5. Tag around. Tag your allies (those whose coin flip landed on the same side as yours), tag your enemies (those who flipped opposite you).
Note that nobody said you had to be a willing participant in this conflict. Be a draftee, be a deserter, be a noncombatant who's found themselves caught up by the war. Be a medic, be a general. Be reluctant allies, be lovers torn apart by principle, be old school rivals who are pleased as punch to have an excuse to shoot at each other.
There are no RNG prompts. There are no limits to what kind of war, when or where it takes place. Do as you please, and be excellent to one another!