If you have taken the December LSAT, February LSAT, and then retake the October LSAT, and do a lot better on the October exam, are your chances of getting accepted to a school limited, just because you took it 3 times, even though you improved?
If you take the LSAT 3 times, your chances of getting into a particular law school are certainly going to be lower than if you had waited and taken the exam only once. This is why I always recommend that students wait to take the exam if they are not fully prepared.
Having said that, you may be able to get into the school that you are interested in… But that depends largely on where you wish to go and how good your LSAT score is when you retake it (among other factors).
Retaking the LSAT once and improving is fairly easy to explain in an addendum to you application… Perhaps you got sick, or had a family tragedy or something else. However, explaining why you didn’t do well on your first two attempts is a bit trickier. If you just weren’t prepared the first two times you took it, that isn’t going to impress many admissions directors. If, however, there were extenuating circumstances that explain the low scores, then it is very important that you truthfully convey that in an addendum.
Also, it is statistically unlikely that any given test-taker will actually earn a significantly higher score when they retake the exam. (see this post for more info)
If you want more targeted advice, please provide more in-depth information: In order to evaluate how your multiple LSAT scores are likely to affect your chances, I would need to know your previous 2 scores, the circumstances that led to your underperformance, a realistic anticipated LSAT range when you retake the LSAT in October, your undergrad GPA, and your target schools. Any other relevant information would also be helpful (URM status, alma mater, etc.) Only with that additional information would I be able to estimate your chances of admission with any accuracy.