Flaw questions hand you a broken argument and ask you to name the break. Most test-takers can feel that something is wrong; the point goes to the one who can say whatin the abstract vocabulary the answer choices use. That translation, from felt wrongness to named error, is the entire skill, and it is why flaw questions are the highest-leverage type in Logical Reasoning: the error patterns they teach you to name are the same ones weaken, strengthen, and assumption questions are built on.

What a Flaw Question Actually Tests

Two things at once: whether you can locate the specific reasoning error, and whether you can recognize it dressed in the exam’s formal language, “takes for granted that,” “confuses a necessary condition for a sufficient one,” “treats evidence that a phenomenon is widespread as evidence about a particular case.” The argument’s error is usually common; the phrasing is what filters test-takers.

How to Identify Flaw Questions

Stems include: “The reasoning in the argument is most vulnerable to criticism on the grounds that”; “describes a flaw in the argument”; “the argument is questionable because it.” Note what the stem promises: the argument is flawed. You are not judging whether, you are identifying which.

The Lovare Method, Four Steps

One: read for the move, not the story. Every argument makes a move from premises to conclusion; flaws live in the move. Two: name the flaw in your own words before touching the choices. “He assumed the only two options are X and Y.” Three: translate to exam dialect. Your phrasing becomes “presents as exhaustive a set of alternatives that may not be.” Four: verify against the stimulus. The credited answer must describe something the argument actually didmany traps describe real flaws the argument never committed.

A Worked Example (Original)

A Calder city councilman argues: “Since the new streetlight program began, reported burglaries have fallen 18 percent. Clearly, better lighting deters burglars.”

Feel the wrongness, then name it: the argument moves from correlation in time to causationignoring alternatives, a police staffing change, a citywide trend, even a change in how burglaries get reported. The credited answer reads something like: “takes for granted that no factor other than the lighting program could account for the decrease.” The classic trap nearby: “relies on statistical evidence drawn from an unrepresentative sample”a genuine flaw type that this argument did not commit. Half of flaw-question skill is refusing answers that describe crimes the defendant didn’t do.

Build the Flaw Vocabulary

A short core list covers most of what the test runs: causal leaps (correlation to causation, reversed cause, ignored alternatives), conditional confusions (necessary versus sufficient, invalid contrapositives), sampling errors (unrepresentative, too small, self-selected), equivocation (one word, two meanings), ad hominem (attacking the speaker, not the claim), false choice (treating two options as the only options), part-to-whole and whole-to-part transfers, and appeal to inappropriate authority. Learn each with one homemade example and its exam-dialect phrasing. This vocabulary is not just for flaw questions, it is the operating system for half the section.

Withheld Tip: keep a “dialect card”, one page mapping plain-English flaw names to the exam’s formal phrasings. Most flaw misses are translation failures, not detection failures: the student saw the error and still picked the wrong description of it. Ten minutes of dialect review per week ends that.

The Traps, Named

The Wrong Crime describes a real flaw the argument never committed, the most common trap on the type. The Half-Truth describes part of what happened with one fatal inaccuracy in the details. The Premise Attack criticizes a premise’s truth when the question asked about the reasoning. The Mirror describes the argument’s structure accurately but as if it were valid.

How to Train It: The Loop Applied

Flaw errors go in the log under two headings: detection (didn’t see the error) and translation (saw it, picked the wrong description). Blind review tells you which student you are, if you fix the miss untimed, your issue is pressure or pacing; if you miss it again calmly, the vocabulary itself is incomplete. Detection problems train with untimed structure-reading; translation problems train with the dialect card. Same wrong bubble, opposite prescriptions, which is the entire reason the Loop separates them.

If You Only Do 3 Things

1. Write your own example of each core flaw type, inventing one teaches more than recognizing ten.
2. Name the flaw aloud, plainly, before reading any answer choice on every flaw question for two weeks.
3. Sort every miss into detection versus translation, and train the one your log actually shows.

Flaw Questions: Quick Answers

How common are flaw questions on the LSAT?

Among the two or three most frequent Logical Reasoning types, and their vocabulary underwrites weaken, strengthen, and parallel-flaw questions, which makes them the best per-hour investment in the section.

Do I need formal logic to answer them?

You need the conditional basics, necessary versus sufficient and the contrapositive, plus the named-flaw vocabulary. Full formal-logic training is unnecessary; precise reading of the argument’s actual move is everything.

Why do two answers always look right?

One describes what the argument did; the other describes a similar crime it didn’t commit. The tiebreaker is always the stimulus: re-read the move, not the choices.

Related Playbooks

• LSAT Parallel Flaw Questions
• LSAT Weaken Questions: The Complete Guide
• Logical Reasoning: The Complete Strategy Hub
• The 12-Week LSAT Study Schedule

Lovare’s Take

Flaw questions are the section’s grammar lessons. Learn to name the ways arguments break and you stop experiencing Logical Reasoning as 25 separate puzzles, it becomes a small set of recurring errors in rotating costumes. That shift, more than any single trick, is what a +16 improvement is made of.