D.L.
My 14 mos old does this too. My solution is that I made her entire room childproof and put a twin sized mattress on the floor. When she wakes up I go in her room, calm her down and then lay down on the mattress and go back to sleep. She plays happily on the floor awhile then come over and cuddles next to me on the bed and falls back asleep. I tried everything including walking, rocking, singing, listening to music and letting her cry before I decide to give in to her need to play at night. I talked to my mom and she says I played at night too when I was a baby. Karma I guess.