At least I think that's what they are called. Anway I plotted one this morning. I thought it was about time as there is lots of stuff coming up in The Novel (ooh very excited that I may have come up with a title too!) and I was getting a bit bogged down in what was going to be revealed when and where and to who, and it was getting in the way of the writing.
I've used a lumpy parabola-shaped one with a gradual climb dotted with crises up to a climax at about 65,000 words and then a steep descent in the aftermath. Sort of like this
Having never written a novel before I am only just getting to grips with large scale plotting and I have found this has really helped. I was very relieved, I have to say, to discover that my novel does have a plot! And it's one that, according to my story arc, can be sustained over 80,000 words without, hopefully, peaking too soon.
The details of the arc may change of course (I did it in pencil just in case) but for now it looks lovely in my notebook with stars along its curve marking significant events and the whole thing neatly divided up into chapters. Now that I've got it in down in grey and white I can get on with writing the bloomin' thing, which is the bit I enjoy