Types of Logic Games
There are four primary types of logic games featured on the LSAT: sequencing games, grouping games, odd games, and hybrid games. Sequencing games, grouping games, and hybrid games make up the overwhelming majority of logic games. But odd games have been popping up on the test more frequently in the past few years than they used too, which makes them important to talk about as well.
In sequencing games, you are required to determine the potential locations of variables lined up in a sequence. This could be a simple as some people standing in a straight line. The rules of sequencing games usually focus on where the variables are allowed to be in the sequence. For example, you might learn in the rules that Harold must be first in line or that Yolanda must be somewhere in front of Steve.
In grouping games, you are asked to sort variables in two or more groups. For example, you might have to sort nine marching band members into brass, woodwind, and percussion sections. Sometimes these logic games only deal with a single group but you must determine which variables are in the group and which variables are not in the group. The rules in these games often rely heavily on conditional reasoning. For example, you might learn that if Glenda is in the brass section then Trent is in the woodwind section.
Odd games rely on logic other than simple sequencing or grouping. The most common are circles games (which require you to sequence variables in a circle) and pattern games (a name often given to logic games that involve some kind of repeating pattern or configuration of variables). But some games seem to defy any helpful category other than being odd.
Hybrid games are combinations the other game types—usually sequencing and grouping. For example, a logic game might require to determine the order in which seven job candidates interviewed as well as which job candidates were hired.
Logic Game Question Types
At the end of each LSAT logic game is a set of 5-7 questions. These questions test your ability to make inferences from the rules. The questions can be broken down into four common categories: “must be true” questions, “could be true” questions, “cannot be true” questions, and rule substitution questions.
Could Be True
“Could be true” questions require you to determine what is possible. For instance, you might see a question like this on the LSAT:
Which of the following could be an accurate schedule for Mary’s meeting?
Notice the word “could” in the question. The answer choices for a question like this will include four schedules that are not possible (given the rules of that particular logic game) and one schedule that is possible.
Let’s look at another example:
Assuming that Mary must discuss the layoffs before discussing the new recycling policy, which of the following could be true about Mary’s meeting schedule?
Again, this question asks about what is possible. But this time there’s a twist: you are given a new rule to work with. You are told here to assume one more rule for this question. The answer choices will include four impossible answers (assuming the new rule) and one answer that is possible with the new rule. But remember that question-specific rules (like this one) cannot be used on other questions. The assumption given in this question only applies to this question.
Must Be True
“Must be true” questions ask you to identify necessary conditions. In other words, the questions require you to pick the answer that cannot be false. It is not enough here for an answer to be possible under that particular games’s rules; it must be impossible for the answer to be false. Simply put, the answer must be true.
Let’s look at an example:
Which of the following must be true about the movies shown on Stanley’s television?
The answers will include 4 answers that are not necessarily true (but perhaps could be!) and one answer that absolutely must be true according to the rules of that particular game. A good way to eliminate answer choices in these questions is to show that the answers could be false. If you can imagine a scenario (while strictly following the rules) in which an answer choice is false, then it is not the answer you are looking for.
“Must be true” questions can also have question-specific rules. For instance:
If Stanley’s television shows Casablanca at 3:00, what must be true about the other movies shown?
You will be given four answers here that could potentially be false (assuming this new rule) and one answer that must be true with this new rule thrown in the mix. You, of course, need to find the answer that must be true.
Cannot Be True
“Cannot be true” questions require you to identify an answer that is not possible under that particular game’s rules; in other words, you need to find the answer that contradicts the rules of the game.
Let’s look at example:
Which of the following cannot be true about the Chattanooga bus routes?
In “cannot be true” questions, you will be given four answers that could be true and one that cannot. To eliminate an answer, you need think of a scenario (within the boundaries of the rules) in which that answer could be true. If an answer is possible, it’s wrong.
“Cannot be true” questions can also feature question-specific rules. For instance:
If the downtown bus leaves the hub at 4:00, what cannot be true about the Chattanooga bus routes?
Just like the other question-specific rules, the new rule applies to this question alone.
Rule substitution questions are a bit strange. These questions require you to replace one of the original rules given to you with a new rule. For example:
Which one of the following, if substituted for the condition that Barney stands before Charles in line, would have the same effect on the ordering of the water fountain line?
You will then be given a list of five potential rules to choose from. You must determine which of the rules is logically equivalent to the original rule. In other words, which rule would give you the exact same logic game?
These questions are tricky, and many student struggle with them. They can be conquered though. The best approach is to use the process of elimination. Work through the answer choices and find answers that allow for game possibilities that the original logic game would not allow. For example, the original logic game might forbid Cathy from standing first in line. So if an answer choice allows Cathy to stand first in line, you know that answer is wrong. Try to find answer choices that contradict the logic game. If you can eliminate four answers, then the remaining answer must be true.
There is a variant of the rule substitution question type that actually gives you a new rule to use. For instance:
If you ignore the condition that Barney stands before Charles in line and instead assume that Charles stands before Victoria, then which of the following must be true?
In this variant, you are told to eliminate an old rule and follow a new rule instead. In order to solve this question, you will need to ignore not only the old rule but every inference you made based on that rule. You will also need to make new inferences based on the new rule.
Just like the question-specific rules, rule substitutions do not carry to other questions. The rule applies to that particular question only.