Every year, more colleges either require or recommend that students who plan to submit ACT scores take the ACT Plus Writing. The exam includes a 30-minute Writing Test that is not part of the regular ACT.
The scoring for the Writing Test does not employ the same 36-point scale used for the English, Reading, Math, and Science Tests. Instead, the Writing Test uses a 12-point scale.
To learn about this scale -- what score is good, what's average, and what's typical for matriculated students -- check out this article on ACT Writing Test scores.
Note that if you take the ACT Plus Writing, your writing score will typically show up about two weeks after the rest of your scores. The reading and scoring of the essays is a time-intensive process.