Rather than each of thousands of plaintiffs repeating the same 100 pages about the product and the defendant's conduct, MDL courts adopt a master complaint containing the shared allegations. Individual plaintiffs then adopt it by reference through a short-form complaint.
The master complaint is where the litigation's core legal theories live — if a motion to dismiss knocks out a theory there, it falls out of every adopted case at once. See also: short-form complaint.
Sources & attribution