well the OP was pretty specific - undamaged plane, no bad guys to be seen, safely landing in an open field, within range of friendly GVs.
Ive only really read the RAF accounts of this kind of thing and the biggest concern for landing on improvised strips/parks/grazing land/football pitches/country house lawns etc. wasnt the uneven ground but soggy patches where the undercarriage would dig in and cause the plane to do an endo.
Then again these accounts invariably end up with the pilot being recovered from the local pub in an advanced state of ... err ... relaxation 
Yes, and my point was that you probably shouldn't be able to land off-runway in most places you can in this game and still maintain your gear. Hell, I've landed on a mountain side and coasted down the mountain all the way to the runway and actually landed kills. Improvised strips are WAY smoother than random fields and forests.
From what I understand, most of the aircraft of the period had
fairly fragile gear, too much lateral force (or even a decent bump) and they'd buckle. I'm assuming this is because of weight saving, but I'm no doctor. I'd be willing to bet that most attempted ditches were either gear up, or if they attempted to land wheels down, with a very generous amount of damage to the undercarriage.
