Once upon a time, I read Sorcery and Cecilia by the lovely Patricia Wrede and Caroline Stevermer. If you haven’t read this, you are missing out. It is marvelous.
It’s an epistolary novel, meaning each person writes letters as their characters and there is no plotting with each other.
Anyway, I got to thinking that I would like to write with someone else. At first, I tried epistolaries myself. The first got, oh, four letters in. We were writing and sending real letters through the mail. On one hand, real mail! On the other hand, it was slow and then you didn’t have a copy of what you’d written. Fail.
Second attempt went better. A friend and I wrote through private messages to each other on a writing community. We got maybe 20K words in before someone hacked the forum and we lost 10-12 letters. Pros: Could get through several letters in a day, could see both sides of the conversation. We didn’t feel like trying to rewrite so many letters, so we let the project die and I later re-wrote the entire story by myself.
At this point, I came to a revelation. I was not Patricia Wrede. My friends were not Caroline Stevermer. The likelihood of us somehow managing to write a cohesive story through letters without talking to each other was probably never going to happen. With the above example, I remember having a plot line in my head and trying to steer my partner to it through the letters, but it was like herding landsquid. (Landsquid hate being herded and they are grumpy. I do not recommend trying.) We were on different pages and there was no way to say “I want to go this direction” without breaking the epistolary rules.
So, time to try something else.
A few months later, mid-2007 or so, Script Frenzy launched. I’d had never written a screenplay but I thought it might be fun, so I recruited a writing friend to work on it with me. It proved to be a rewarding experience, and we’ve been writing on and off together since. (Not on screenplays, though. That went in a drawer and hasn’t come out since.)
We’ve written a variety of ways – epistolary (though true plottiness still eludes me), alternating character viewpoints with each of us writing one character, and a neutral viewpoint that we both wrote.
While I still prefer to write alone on most projects, I’ve found this to be a rewarding experience. When we get stuck, we can bounce ideas off each other. We can catch POV errors and typoes for each other. We can challenge each other to new heights. (Plus she always lets me write the horribly embarrassing parts. ♥)
Not to say it always goes smoothly. When something goes wrong in one person’s life we’re both in limbo. We’ve gotten into fights about story direction, character issues, plot holes. Luckily we’re fairly compatible so even after we’ve had to take a step back we can usually work out some sort of compromise and move forward.
Overall, I would say that the bonuses of working collaboratively outweigh the negative.
Have you written with a partner? Would you do it again?
Discuss how interest in it started, how things have gone, etc.
Where Landsquid Fear to Tread 
