LSAT Logic Game Rule Substitution Drill

People generally find rule substitution questions difficult on the LSAT. Fortunately, you can get around this with a drill.

First, a bit of background theory about how LSAT improvement works. When you first start on the LSAT, everything is new. But as you repeat tests, you start to see patterns, and improve quickly, at least at the easy-to-medium difficulty concepts, and the common concepts.

For harder and rare concepts, you have to do more specific study. But the easy concepts, you get more or less automatically.

How does this apply to rule substitution questions? Everyone thinks they’re hard. I disagree. I think they are easy, but uncommon. In other words, the problem is that you don’t see enough of this to learn the patterns.

People drill LR question types. And they drill logic games types. But almost nobody drills LG rule substitution questions.

If you simply do bunch of them in a row and really mastery them, you’ll start to see the patterns.

How to Drill Rule substation questions on the LSAT

Rule substitution questions generally have only appeared on recent LSATs, and they’ve become more frequent as time has gone on. So that means you can only practice them on recent LSATs.

1. You should do this drill with LSATs you’ve already done. Don’t burn a whole logic games section just to do a single question. Here’s what to do:
2. 1. Make a list of the PTs you’ve done between LSAT 62-80
3. Compare them to the list below, and make a list of 5-10 games where you have done the PT and there is a rule substitution question
4. Setup the games, and then do only the rule substitution question
5. Then, read the explanation
6. Redo the question, trying to look for the pattern in the explanation
7. As you start to get the hang of it, stop referring to the explanations. Instead, make sure you feel fully confident in understanding the question, repeating it if necessary. Only refer to the explanations to confirm you understood everything.
8. Continue doing this until you start to get a feel for the patterns

A couple of tips while doing this:

• You should feel confident in your setup when you do the rule substitution questions. So you may also want to do the first question of the game + any other questions you need to do to feel you’ve got a hang of it. Feel free to check answers on those to confirm you’ve got it. But don’t go overboard: once you feel you’ve understood, head straight for the rule substitution.
• As you get the hang of it, you should at least loosely time yourself on the rule substitution part. It’s no good to get the questions right but need five minutes. The goal of the drill is to learn how to get them right quickly.

Strategies for Rule Substitution

The key thing to do is that they won’t be replacing the rule with some crazy insane thing in isolation. To replace it, they have to use the other rules to generate the same effect.

Example: 

1. J is immediately before L
2. L is somewhere before Q
3. X cannot be before Q
4. Z is also in the game

Suppose I asked you to replace the second rule. The only way to do it is to use the first rule, and say “J is somewhere before Q”. We end up with JL – Q – X with either version.

This is a simple example, but basically every rule substitution question must do the same thing. So if you know the existing rules and their effects very well, then it becomes easier to see how the substitution happens.

If you’re stuck, you can also brute force answers with these two methods:

• The right answer has to allow everything normally allowed. Suppose an answer said: Z is after L and before Q. This meets the “L is before Q” rule, but it forces Z to be before Q. Normally, Z can be anywhere.
• The right answer must forbid everything normally forbidden. So, you can’t have a rule that says “X is right before L, and X is before Q”. That contradicts rule 3.

These are both ways of saying: the right answer can’t contradict the existing rules. Many answers do. This also means that any valid scenario you constructed during the game must also be valid.

The questions for the drill are below. Good luck!

LSAT Rule Substitution Questions and Explanations Drill

• PT 61, Section III, #11 Explanation
• PT 62, Section III, #6 Explanation
• PT 64 Section II, #12 Explanation
• PT 65 Section II, #23 Explanation
• PT 66 Section III, #11 Explanation
• PT 69 Section II, #17 Explanation
• PT 70 Section III, #7 Explanation
• PT 71 Section II, #5 Explanation
• PT 71 Section II, #16 Explanation
• PT 72 Section IV, #13 Explanation
• PT 74 Section IV, #23 Explanation
• PT 75 Section IV, #18 Explanation
• PT 76 Section III, #23 Explanation
• PT 77 Section III, #23 Explanation
• PT 78 Section II, #23 Explanation
• PT 80, Section III, #11 Explanation