When she climbs out of her crib, it's time to get her a different bed. Climbing is easier than getting down safely. As she'll climb out anyway, make it safe by getting her a bed that isn't dangerous to get out off.
About the getting out, put her back (repeatedly if needed) as answered by others.
In addition to the suggestions of putting her back in, it's also a good idea to disassociate the bedroom with playing. Keep a separate play room (or, if you don't have the extra rooms, an area to keep her toys and whatnot in a non-bedroom place in the house) where all her toys are. That way, there's nothing worthwhile getting out of bed for. That also reinforces the "bedroom = sleep" connotation.
We always let our son play for a few hours after we put him in bed at 8. We would just laugh and take pictures of him fallen asleep in the middle of his pile of toys in night. He never seemed to be tired during the day, he just caught up on his sleep during nap time.
Our second and third children haven't yet decided that they want to climb out of their beds and play. I suggest letting them play.
Pick your battles. I'm sure that you've got enough war with them during the day.
Why not let her sleep on the floor? Why not let her sleep with you?
Be sure to have a good unwinding portion at the end of the day. Turn the TV/radio down, turn down the lights, make it calming, and then do the nighttime routine. If she is still getting up in the night to play, she is probably getting too much sleep during the day. Be tons of fun all day, lots of play, lots of noise, play outside where it is light, then prepare for bed by unwinding.