Script written from scratch for screen — no source material, no adaptation. Gives writers like Kaufman creative control over structure and dialogue.
On set, you quickly notice whether you're working with an original screenplay or an adaptation – the energy is different. An original screenplay doesn't arise from a novel, a true story, or existing material, but grows directly from the author's imagination for the medium of film. This means: from the first sentence, the writer thinks in images, cuts, in what the camera shows and what it conceals. There's no book page to "adapt"; no literary source that purists will defend.
Practically, this means a different freedom – and a different responsibility – for the production. The author has already conceived the scenes within cinematic space. The dialogues aren't distilled from prose but originated directly as spoken language. This often saves time in editing because the rhythms are already right. At the same time, as a director or DoP, you carry the full burden: there's no literary source you can fall back on if something doesn't work. The original screenplay is the material itself – not an external interpretation.
The most famous examples show this: Charlie Kaufman writes original screenplays that are so idiosyncratic and formally experimental that they present entirely new demands on set – Adaptation or Being John Malkovich required directors brave enough to take on the experiment. Christopher Nolan works almost exclusively with original screenplays; Inception or Memento were intellectual constructs that only existed in the screenplay before the first camera rolled. This means the creative space between writing and shooting is maximized – but the communication between screenwriter and director must be absolutely solid.
In terms of budget and financing, an original screenplay is often riskier than an adaptation: you can't point to the success of a novel or a film. On the other hand, you're not bound by the expectations of the source material. Casting works differently – you're not looking for someone to "portray" a literary character, but for someone for whom the character was written. It's subtle, but it changes everything.