: A baby is abandoned by his mother, who is unable to take care of him, and placed on a doorstep for the owners of the house to raise.
- Straight: Bob's mother leaves him at the doorsteps of his aunt and uncle's home.
- Exaggerated: Babies are piled on the doorstep, resulting in a Wave of Babies when the door is opened.
- Downplayed: The new parents of Bob know they'll be adopting a baby and greet his mother or a social worker at the door with Bob.
- Justified: The doorstep is a church or orphanage and it is understood in that town that babies left there have been surrendered for adoption.
- Bob is an adult and can no longer take care of his aging mother, so he leaves her on someone's doorstep.
- Alternately: a mother leaves the baby on her doorstep, in hopes that someone else will take it.
- Alternatively to that: Someone goes door to door asking for unwanted children.
- Or: Becky needs help getting pregnant, so she sits herself down on the nearest doorstep and waits.
- Subverted: Bob's mother leaves him at the doorsteps of his aunt and uncle's home...before they arrive back home, Bob is stolen by a thief.
- Double Subverted: The thief changes his mind and leaves Bob on another doorstep.
- Parodied: The kindly parents take the infant in. The next day, a dozen more babies of different species are waiting for them on the doorstep.
- Zig Zagged: The baby is sick, but is healed, but gets sick again when it isn't on the doorstep, and gets thrown out for being too much of a hassle, whereupon it gets sick again.
- The baby is put up for adoption the normal way.
- Or the mother just keeps the baby.
- Enforced: "If they just find the baby in the open, they may assume it's just lost. If the baby's on the doorstep, people will understand it was left for them to find."
- Lampshaded: "Anything on the doorstep this morning? Milk? Newspaper? Baby?"
- Invoked: The father kidnaps the baby and places him on the doorstep.
- Exploited: A desperate, infertile couple puts a sign up on their door requesting foundlings.
- Defied: The mother abandons the child where she knows it will not be discovered.
- Discussed: ???
- Conversed: ???
- The baby dies of exposure.
- Alternatively, the baby is very sick and malnourished.
- Alternatively, the owners of the house raise the baby as a Sex Slave.
- The baby is reared back to health.
- The baby escapes the crazed family and finds refuge somewhere else.
Please, kind sir, won't you take this child back with you to Doorstop Baby