The SAT is not a calligraphy test, clearly. So if you’re reading this at all, I’ll assume that you don’t have the neatest handwriting in the world, and you’re concerned it might affect your score.
Officially, the answer to the question is no—the SAT does not reward or punish students based off their handwriting. Again, that’s officially. The truth is not always “official,” though.
Undecipherable essays lose points
SAT essay graders are really well practiced at reading all kinds of handwriting. Going through as many essays as they do means they have to be able to read almost anything. Having done plenty of that myself, I can tell you that yes, it does get easier to read even the strangest handwriting with practice.
The grader will never just give up on reading something that’s hard to decipher. No matter how bad your handwriting is, as long as it really is English, they’ll be able to get the idea
That being said, I wouldn’t hesitate even a moment to say that difficult to read essays lose points. The reason is as simple as you’d think; not being able to read even just a word or two takes away meaning from a sentence, and that takes away from the strength and fluency of the surrounding argument. Even if the case made in the essay is eloquent and well-supported, it ends up feeling fragmented when individual words are lost.
Essays that graders can read at a natural pace, on the other hand, tend to feel more lucid. It’s a lot easier to hear the writer’s voice when you don’t have to put any effort into understanding the handwriting.
How can I write more clearly?
Have you ever had to read the writing of your classmates? There’s the girl that dots every i with a heart, for one. Every o on her page looks like it could win a circle-drawing contest. Take that and compare it to what the quiet guy in the corner is writing. Is that Sanskrit? Elfish?
What makes the easy-to-read writing so digestible? There are a few things that definitely help.
1) Larger print
2) Round, open letters
3) Even spacing between letters
This isn’t about staying on the line, slanting your writing gracefully, or printing in block letters. It’s about making space: space within letters and space between letters.
Legible writing can be ugly. If you have chicken scratch for handwriting, don’t worry about making it into elegant cursive. Instead, just be sure you make the letters individually distinguishable. Make them bigger and more separate.
If you like your tiny, cramped writing how it is, that’s fine. Just not on the SAT, please. You get lots of space to write your essay, so use it.