'''Basic Trope''': 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 WaveOfBabies 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 [[LawOfInverseFertility 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 SexSlave.
** 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 DoorstopBaby?
%% Optional items, added after Conversed, at your discretion:
%%* '''Implied''': ???
%%* '''Plotted A Good Waste''': ???
%%* '''Played For Laughs''': ???
%%* '''Played For Drama''': ???