How to Diagram Common LSAT Logic Games

Your master diagram should be built exclusively from information provided in the game setup and the rules. Label it clearly as “Master Diagram” and keep it separated from the individual question diagrams.

Many questions will provide additional information that can be drawn into a question-specific diagram. Question-specific diagrams are simply master diagrams with new information added. Label them clearly with the question number they represent and try to draw them as close to the applicable question as possible.

Separating your diagrams and labeling them clearly is helpful for two reasons. First, it prevents you from accidentally applying information from one question to another question where it doesn’t belong. Second, it allows you to keep track of deductions you’ve made in previous questions, and then use those same deductions to answer later questions more quickly. (You don’t want to miss a point because you looked at the wrong diagram!)

Now, let’s jump to another fun part of Logic Games – Formal Logic!

Formal logic appears in most, if not all, Logic Games—most often in the form of if/then, only if, if and only if, or unless statements. Knowing the nuanced differences between these types of statements will help you interpret rules and draw diagrams more accurately.

In fact, familiarity with formal logic is probably the single most valuable tool on the LSAT Logic Games section. Also, knowing formal logic will improve not only your Logic Games score, but also, your Logical Reasoning score. And who doesn’t want that? So, be sure to review Magoosh’s posts on formal logic: If, Only if, and If and Only If on the LSAT, and If/Then Statements and Contrapositives.

If you notice a particular rule or piece of information introduced in a question restricts the number of possible solutions to only 2 or 3, draw each one out completely. For example, if your task is to arrange guests around a table, and a rule tells you that Bob must sit next to Francine, that leaves only two possibilities. In the first, Bob sits immediately to the left of Francine. In the second, Bob sits immediately to the right of Francine. Rather than trying to remember that fact, draw two tables and place Bob and Francine at each based on the two possibilities. This simple step will save you a lot of time and help you get more points!

Once you’ve drawn out these limited options, make sure to incorporate all the other rules into each option. You’ll often find you now have enough information to fill in most—if not all—of at least one of the options. As a result, the related questions will likely be very easy to answer. And who doesn’t want a few easy LSAT questions?

Sequencing games have only one set of variables and one set of ordered spaces in which to place them. Variables refers to the made-up names that all start with a different letter and aren’t inherently ordered. For example, numbers, days of the week, or months of the year are inherently ordered, while people and events are not inherently ordered.

A great way to quickly identify a Sequencing game is to look for the ratio of spaces to variables. Anything with a 1:1 ratio of variables to spaces is Sequencing. For example, if there are 6 trains arriving at 6 different times, it’s a Sequencing game. Rarely, there’ll be one extra variable and you’ll be required to assign two variables to one space. That’s still Sequencing, and you can just treat that space as divided into two sub-spaces.

Since all you’re doing is putting things in order, you simply need to draw out your spaces in a line and label them clearly. List out your variables somewhere nearby, and you’re ready to start working through the rules.

Here’s an example of how to diagram a student’s class schedule if we know the student is taking 7 courses, and that they’re Algebra, Biology, English, History, Political Science, Psychology, and Water Polo.

Like Sequencing games, Grouping games have only one set of variables. Unlike Sequencing games, Grouping games do not have a 1:1 ratio of variables to available spaces. Instead, they provide you with only 2 or 3 categories where your variables will be placed.

Most of the time these categories are obvious. You’re asked to place people on 2 or 3 different teams or pay bills on 2 or 3 different days of the week. On rare occasions, though, you’re given a scenario where you have to select some variables but not others. Don’t be fooled! This is just a Grouping game with 2 categories: one that includes the variables and one that doesn’t.

All Grouping games have the same basic diagram, which is just a set of labeled categories like the one below.

But you won’t stop there, since the game will always provide you with more information that can be incorporated into your diagram before you even get to the rules. There are two common types of Grouping games, Fixed and Floating, and each has its own special details in the diagram.

In a Fixed Grouping game, the setup tells you exactly how many variables will be assigned to each group. In this case, you represent those variables by drawing the appropriate number of slots in each category. Your sketch will look something like this:

In a Floating Grouping game, you won’t necessarily know how many variables go in each category. However, there are usually some hints as to the minimum or maximum number that can be assigned to any given category. So, you can draw slots where appropriate and use question marks to represent places where variables may or may not be assigned.

Matching Games always contain two different sets of variables (for example, people and pets, or shirts and pants), but they do not contain any ordered spaces. You’ll be asked to pair the sets of variables with each other, but you won’t be required to arrange them in a particular order.

The key to diagramming a Matching game is to set up a table. List one set of variables vertically and list the other set horizontally, creating a grid of boxes in which you can place an “X” or a check mark to indicate whether or not a particular pairing is selected. That’s about all there is to it!

The trick with mastering Matching games is not in setting up the basic diagram, but in building rules and inferences into it.

Quick tip: pay attention to whether each variable can be used once or more than once. If a variable can only be used once, then you can places Xes in its entire row or column as soon as you’ve placed at least one check mark in that row or column. However, if the variable can be used multiple times, you lose that advantage.

Be sure to practice Matching games so you can grab these points on test day!

Like Matching games, Sequencing/Matching hybrids will have two sets of variables. But they require you to place the sets of variables in order. For example, they might ask you to schedule speakers in a lecture series, and then assign each speaker an auditorium in which to present. Often one set of variables will contain fewer items than the other set, meaning that at least some items in the smaller set will have to be used multiple times.

A common mistake test-takers make is to attempt to set these up as regular Matching games using a grid. But because the grid doesn’t allow you to represent order, you end up struggling more than you have to.

In a Sequencing/Matching hybrid, I’d recommend representing the sequencing component horizontally, like you would a timeline. In other words, start with a Sequencing diagram, and build from there.

First, you set out your row of spaces to house the first set of variables (this should be the larger set if they are different sizes; otherwise, it probably doesn’t matter which one goes first). Then, you simply duplicate that with another row of spaces directly beneath it, where you’ll place the second set of variables. If two variables from different sets are paired together, then they should occupy spaces directly above/below one another.

Once you have this basic setup, you can start working through the rules. The rules may refer to either set of variables. But don’t worry—you’re prepared to handle that because you can place members from each set in their respective row, wherever the rule stipulates they should go.

Great job with your first hybrid game type!

Let’s take a look at another hybrid game you’re likely to see on the LSAT.

Grouping/Sequencing hybrids will contain only one set of variables, but you will be asked to place those variables into groups, some or all of which may have internal order. For example, you may have to schedule which movies play at a theater on Friday, Saturday, and Sunday (so you have 3 categories), and then determine when each movie will play (at 7pm, 9pm, or 11pm).

As with regular Grouping games, it’s possible to have either a fixed or floating element, meaning you may or may not know how many variables are assigned to each category. That’s why these games can be tricky to diagram. But don’t worry. We’ve got you covered—read on for tips on diagramming this game type.

The Grouping action will almost always be the first action in a Grouping/Sequencing game. You could be asked to arrange items and then group them (an example would be determining the order of lectures and then deciding how many are scheduled in the morning and how many in the evening), but that’s uncommon. In a grouping/sequencing game, start with a standard Grouping diagram of categories. Then, you can build internal order vertically or horizontally (whichever you prefer) in each category.

Whew, that’s a lot of information. But you can see from the sketch below that the diagram will still be pretty simple!

When it’s a fixed grouping game, it’s pretty easy to draw the exact number of slots you need and label each clearly. If it’s a floating grouping game, you may need to use some question marks again to denote what you do and don’t know. Either way, practice makes perfect so be sure to practice lots of hybrid games.