As mentioned above, it might depend on the barn conditions. If predators are not a big problem then I think a 3-legged cat could adapt just fine. I have a declawed barn cat. He was a "free-to-good-home" kitty due to allergies and he was already declawed when he came here. He was supposed to be a house cat, but decided that fresh laundry was a nice litter box so he had to go out. He has done fine out there the past 5 years and he is actually one of the better hunters...I see him with mice all the time. I think they can adapt, but if the house is a possibility I'd go that route first. And if you do put it outside please watch it closely at first just to make sure it is adapting. Good luck!