LSAT In/Out Grouping Games: The Complete Strategy Guide

An in/out game presents a pool of entities and asks you to sort them into two groups: selected (in) and not selected (out). Unlike multi-group assignment games, every entity has exactly one destination — in or out. The question is which.

What makes in/out games distinctive is that the rules almost always take the form of conditional statements: 'if A is selected, B is not,' 'if C is not selected, D is selected.' This makes them feel like a logic puzzle where every move triggers a chain reaction.

A typical setup: 'A cooking show will feature exactly four of the following seven ingredients: basil, cardamom, dill, fennel, ginger, horseradish, and juniper. The following conditions apply.' What follows are conditionals, co-occurrence rules, and exclusion rules — the building blocks of every in/out game.

Draw two columns: 'In' and 'Out.' If the game specifies an exact number of selections (e.g., exactly four of seven), label the In column with four slots. Write the full roster above: B C D F G H J.

As you make deductions, place confirmed entities in their column. Entities that are not yet determined stay in the roster. Mark them with a question mark if it helps to distinguish 'undetermined' from 'confirmed.'

Unlike sequencing diagrams, there are no slots within each column — the internal order inside 'In' or 'Out' does not matter.

Every conditional rule in an in/out game must be written with its contrapositive. This is not optional — the contrapositive is tested directly on many questions.

'If basil is selected, cardamom is not selected' → B → ¬C. Contrapositive: C → ¬B.

'If dill is not selected, fennel is selected' → ¬D → F. Contrapositive: ¬F → D.

Write both lines for every rule before you touch the questions. It takes ten seconds per rule and prevents the most common in/out error: misreading the direction of a constraint.

In/out games with many conditional rules often support long deduction chains. If rule 1 says A → ¬B and rule 2 says ¬B → C, then selecting A forces C to be selected as well. Write this chain: A → ¬B → C.

Chains also work through the contrapositive: ¬C → B → ¬A. If C is out, B must be in, and A must be out.

Look for chains that 'close' — a chain that forces an entity to be simultaneously in and out. If selecting A ultimately forces A itself to be excluded, then A can never be selected. This is a critical deduction that eliminates whole scenarios.

Setup: Six athletes — P, Q, R, S, T, U — are considered for a relay team. Exactly three are chosen. Rules: (1) If P is chosen, Q is not. (2) If R is chosen, S is chosen. (3) If T is not chosen, U is chosen. (4) Q and S are not both chosen.

Conditionals written out: (1) P → ¬Q; contra: Q → ¬P. (2) R → S; contra: ¬S → ¬R. (3) ¬T → U; contra: ¬U → T. (4) Q → ¬S; contra: S → ¬Q.

Chain from rules 2 and 4: R → S → ¬Q. So selecting R forces S in and Q out. Also from rule 1's contrapositive: Q → ¬P. So if Q is out anyway (due to R being selected), no direct constraint on P yet.

Test: Can R be selected? R forces S and ¬Q. We need one more from {P, T, U} with T/U governed by rule 3. At least one of T or U must be chosen. So the third spot goes to T or U (or both, but we only have one slot). One valid team: R S T. Another: R S U. Both work — check all four rules.

Test: Can Q be selected? Q → ¬P and ¬S → ¬R. So Q is in, P is out, and if S is forced out by rule 4 (Q → ¬S), then R is also out. Remaining entities available: Q, T, U (plus no P, R, S). We need three: Q T U. Check rule 3: ¬T → U. T is in, so this rule is satisfied regardless. Valid: Q T U.

Always verify that the number of required selections is achievable after your deductions. If the game requires exactly four to be selected and your deductions force five into the In column, you made an error somewhere.

Also verify the minimum: if the game says at least two must be selected and your deductions force six into the Out column, you have a contradiction. These number checks catch errors before they propagate through multiple questions.