Re-taking a practice test you've already seen feels efficient — familiar material, a chance to “prove” your improvement — but it measures something meaningfully different from what a fresh test measures, and confusing the two can distort your sense of readiness.
On a repeat attempt, especially within a few weeks of the first, you're drawing on two overlapping resources: your actual reasoning skill, and your memory of the correct answer from last time. The score you get back is a blend of both — and there's no way to cleanly separate how much of your improvement is real skill growth versus recall.
You're not consciously thinking “I remember this is C” — the recognition is often subtle and unconscious, showing up as an answer choice “feeling right” faster than it should. This makes the inflated score feel completely legitimate, which is exactly what makes it dangerous as a readiness signal.
There's no universal number, but it's common for a repeat attempt within a month of the first to show a noticeably better score than a genuinely fresh test would — sometimes several points on the scaled range. The closer together the two attempts, and the more review you did between them, the larger this effect tends to be.
Repeats aren't worthless — they're useful for drilling specific question types, building timing stamina, and reinforcing content you struggled with. What they're NOT good for is answering the question “what would I actually score on a real, unseen LSAT right now,” which is the question that matters most as test day approaches.
If you're trying to decide whether you're ready for the real thing, a score from a test you've seen before — even weeks ago — should be discounted relative to a genuinely fresh attempt. When in doubt, treat repeat-test scores as a floor, not a reliable estimate of your true current level.