A word war is where you set a time limit or a word limit and both of you write at the same, then the winner is the first to reach the word limit or the person with the most words when the time runs out. They're really fun.
“Rise like Lions after slumber
In unvanquishable number.
Shake your chains to earth like dew
Which in sleep had fallen on you—
Ye are many—they are few.” — Mary Shelly