According to the National Weather Service, by the time we had quit playing, we had had 1.32 inches in previous 9 hours; 1.25 of that in the previous 6. And we were playing on a grass and dirt^Wmud field. (Grass where the marchers don't spend much time; mud where they do.)
Eleven people showed up; and I think it those two games were about the most fun I've ever had, despite not being able to see the Frisbee half the time (bad lighting) and getting covered in mud, grass, and the like. I managed not to collide with anyone (although I did come within inches once), and I don't recall spending more than the usual quantity of time on the ground. There were some pretty impressive falls, both in our group, and in the group of people playing football just before we started. I mostly managed to avoid that fate; maybe my habit of always sliding to a stop is a good thing. It did come back to bite me once, though. When trying to stop quickly, I drop down on one or both knees, and slide. Well, this particular time, I planted my knee right into a mud puddle, and got one quite ... nice shower.
 There's a reason I always wear pants, and never shorts.
 When the ground is slippery, this is by far the fastest way of stopping; beating out both sliding on my feet and continuing to run as I slow down. Although less controlled than the second option, it eliminates the very real possibility of falling that comes with attempting to stay on one's feet, and, given the available traction, the third simply did not work.