The answer, as usual, is "it depends." It depends primarily on whether that 158 is a good score, or a bad score, for you. And there are a couple other considerations as well.
What's the average of your past three timed practice test scores?
This is the most important question. If you've been averaging 158 or lower on your practice tests, and you got a 158 on the real thing, then you're not a very good candidate for major improvement on a retake. Did you study hard this time? Did you take a class? Did you do the homework? If you did all that, and you're not planning on doing anything differently next time, then you shouldn't expect to get a score that's wildly better than your practice test average. In fact, you're even money (or better) to do worse if you retake the test.
If, on the other hand, you averaged 164 on your last three practice tests, and scored 158 on your actual test, then you're a terrific candidate for improvement on a retake. I'm always surprised at students who decide not to retake the test in this situation; I really think they're selling themselves short. If you can do it on a timed practice test, then you can do it on the real thing. Sure, it might take you multiple tries.
We all have good days and bad days on practice tests, so why wouldn't this same thing happen on the real test? If your score is way worse than your actual level of ability, as indicated by your practice test scores, then by all means retake the test. I hate to see students rush into law school applications with an LSAT score that I know they can beat. There's a huge difference between a 158 and a 164. Take your time, retake the test, and apply when you're ready.
Where are you applying?
Most schools (except for the very, very top ones) only care about your highest LSAT score. This is certainly the case at UC Hastings, for example. Here's a list of what law school admissions folks have said on the topic. If the schools you're applying to only take the highest score, then why wouldn't you retake the test if you think you can do better? The only downsides are the registration fee and a lost Saturday. The potential upside is huge.
When are you applying?
To give yourself the best chances of admission and scholarships, you need to apply early in the rolling admissions cycle. I try to tell my students that their applications, ideally, would be done by September of the year prior to the year they want to go to school. This always shocks some people, but the best scholarship offers and the best placements result from applying broadly (~30 schools) at the very beginning of the admissions window.
This is where many students make their biggest mistake--everybody seems to be in an awful goddamn hurry. Many 20-somethings think that if they don't go to law school now they are going to significantly delay their progress in life. This is nonsense. If you wait an additional year, and end up going to a better school and/or with a scholarship, you're going to be way further along in life than you'd be if you rushed into a shitty school and $150,000 of debt. This is the biggest investment you'll ever make, other than possibly a house. Take your time and do it right.
I'm happy to entertain specific questions on this topic, from existing students or random strangers. Leave a comment or send me an email. I'm here to help.
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