Law school applicants are a competitive lot. They are always trying to get the upper hand. Therefore it is no surprise that I occasionally hear the questions, "Which one of the four yearly LSATs is the easiest? Some LSATs are easier than others, right?" The short answer to this question is, "No, no test is easier than any other." However, this can be misleading. This does not mean that all tests are EXACTLY the same difficulty, as that is not possible. It is quite challenging to determine if two questions will be the same difficulty to the testing populace, so determining if complete tests are exactly the same becomes a supreme effort. There is also the issue of personal variation and opinion. If you allow one person to take two tests of about 100 questions each and then ask them which one was more difficult, they are going to express an opinion. Factors such as timing mishaps, fatigue, and a few really difficult questions will inevitably lead them to say one test was harder than the other. However, the very next person might feel the exact opposite about the degrees of difficulty. In short, all people do not unanimously agree about the complexity of a given question, and thus the amount of trouble they have with it will vary as well.
Hypothetical situation: Two test takers are completing the LSAT, and we review two particular questions. Both questions are Logical Reasoning, the first being a low difficulty Parallel Reasoning and the second being an ogre of an Inference. The first person is well prepared for the test. She has taken a Kaplan course and spent countless hours mastering the LSAT. She flies through the Parallel Reasoning question getting a quick point towards her score. Though Parallel Reasoning is widely considered one of the hardest question types on the test, she was ready. The Inference question gives her trouble, and it becomes one of the few questions that she misses. This scenario is something the test makers expected. Now our second person did not prepare very well. He has no idea how to answer Parallel Reasoning questions, so he misses one that he could have gotten easily. The monster Inference question comes around and he gets lucky. His goldfish Deloris just won Best-In-Show and he selects (D) as a tribute. Unfortunately, he does not get bonus points for guessing correctly on a really hard one. He only gets a few questions correct, and so his score is far below the first test taker. The moral of the story is this: even if test makers believe that the difficulty of questions on two given tests is virtually exact, the unpredictability of a given day’s test takers is going to create variation.
Due to this potential for unpredictability, the LSAT utilizes a scaled score. Your percentile score is based on how you did in comparison to other test takers on that particular test. For this reason, if a test happens to be marginally more difficult or less difficult, your percentile score would be the same because it will still be based upon your success relative to the others. Assigning the label of "more difficult" to a test just means that that particular test required fewer correct answers to attain a 50th percentile score, a 151. On average it takes 61 correct answers to achieve a 151. On some tests that number might be 60 and on some tests that number might be 62. It is not an exact science, and student variation will create different interpretations of test difficulty.
The important thing to keep in mind is that though one test might be slightly more difficult in your own opinion, your score would still reflect your capabilities in relation to other test takers. The LSAT is a standardized test, and thus the content is predictable. If you prepare yourself effectively, then you will be ready for any and all questions that the LSAT throws your way, regardless of the difficulty.