They're like one of those old video games where you control your character through a series of suggested actions to take, like 'Lift boulder' or 'Head East' normally in the fashion of a verb followed by a noun. You can find them among the internet nowadays, such as
MS Paint Adventures, Ruby Quest, and White Room to list a few. It works as such: A single artist or a small group of artists draw the first image, usually giving you a quick summary of the area the main character is in. Someone then puts up a suggestion and the artist(s) then create the next image, with some sort of text below the image to assist with describing the repercussions of the suggestion.
Here's an example:
> You are Ember Firethroat, an elementalist who commands fire. You awaken in your room to the sun's rays shining through your window. You stand up from your bed and examine the room about you, spotting the rather obvious window and door which le...
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