Weaken is one of the two or three most common question types you'll see across the LSAT's two scored Logical Reasoning sections, and it's the type where sloppy thinking costs the most points. The trap is subtle: your instinct is to look for the choice that feels negative or argumentative, when what the test actually rewards is surgical precision — the one fact that pries apart the argument's evidence from its conclusion. This set is built to train that instinct. Ten original questions, ordered roughly from approachable to nasty, each with a full explanation that shows you not just the answer but the reasoning move behind it.

Before you dive in, a quick reminder on how these are written. Every question below is 100% original, written in the style of the LSAT — never a reproduction of a real LSAC question. Use them to build the skill. When you want to measure yourself against scored, official material, drill on LSAC's LawHub, which is the only place to get real released PrepTest questions.

A Quick Method Refresher Before You Drill

Run every Weaken question through the same four steps. Speed comes from consistency, not from shortcuts.

1. Find the conclusion. Read the stimulus and identify exactly what the author is trying to convince you of. Underline it mentally. Everything else is evidence.
2. Find the gap. Ask: what does the author have to assume for this evidence to actually support this conclusion? That assumption is the argument's soft underbelly.
3. Prephrase the attack. Before looking at the choices, predict how you'd break the argument — usually an alternative cause, a counterexample, or a fact that shows the assumption is false.
4. Test each choice against the conclusion. Ask of every answer: "If this were true, would I be less confident in the conclusion?" If yes, it's a contender. If it supports the argument, is irrelevant, or attacks a premise you must accept, cross it out.

Read the Stem Carefully

Weaken stems come in several flavors. Learn to spot all of them: "Which one of the following, if true, most weakens the argument?" — "...most seriously undermines the reasoning?" — "...most calls into question the conclusion?" — "...casts the most doubt on the argument above?" The critical phrase is almost always "if true." That phrase tells you to accept the answer choice as a given fact and ask what it does to the argument. Never argue with the answer choices — accept them and measure their impact.

The Core Trap Patterns

As you work through the set, watch for these four wrong-answer types. They account for the overwhelming majority of missed Weaken questions:

• The Reverse. An answer that actually strengthens the argument. Under time pressure, a strong-sounding relevant statement is tempting even when it cuts the wrong way. Always check direction.
• The Out-of-Scope. An answer about something the conclusion doesn't cover — a different population, a different time period, a different claim.
• The Premise-Attacker That Isn't Allowed. On Weaken, you generally can weaken by challenging the link, not by disputing a stated fact you're told to accept. Be careful: attacking whether a premise is relevant is fair; simply denying a stated fact usually isn't the trap you think.
• The Too-Weak / Too-Specific. An answer that's technically relevant but so narrow ("in one case," "a single individual") that it barely moves the needle compared to a broader, more damaging choice.

The Practice Set

Work each question in about 1 minute 15 seconds. Prephrase before reading the choices. Then read the full explanation — including why the wrong answers are wrong, which is where the real learning happens. The ten questions and answers are listed below; use the answer key and explanations in the practice section that follows.

Question 1

A city council member argues: "Ever since the downtown district installed brighter streetlights last year, reported nighttime muggings have dropped by 30 percent. Clearly, the brighter lighting is deterring criminals. We should install the same lighting in every neighborhood."

Question 2

"Employees who take a full lunch break away from their desks report higher job satisfaction than those who eat while working. Therefore, requiring all employees to take a full lunch break away from their desks would raise overall job satisfaction at the company."

Question 3

"A recent study found that people who drink two cups of coffee a day live, on average, three years longer than people who drink no coffee. Coffee, then, must contain compounds that extend the human lifespan."

Question 4

"Our new textbook must be more effective than the old one. Since the school adopted it, the average score on the state math exam has risen by twelve points."

Question 5

"The novel cannot have been written by Harwell. Every book Harwell is known to have written contains at least one chapter set in Paris, and this novel contains no such chapter."

Question 6

"A software company found that projects led by managers who hold weekly one-on-one meetings with team members are completed on schedule 80 percent of the time, while projects led by managers who don't hold such meetings finish on schedule only 50 percent of the time. To improve on-time delivery, the company should require all managers to hold weekly one-on-ones."

Question 7

"Region A has far fewer cases of a certain respiratory illness than Region B. Region A also has a much higher rate of vaccination against that illness. Therefore, the vaccine is effective at preventing the illness."

Question 8

"The mayor claims her tax cut caused the surge in local business openings this year. But the tax cut only took effect two months ago, and most of the new businesses opened before then. So the mayor is wrong: the tax cut did not cause the surge."

Question 9

"Advertisements for the supplement Vitalax feature testimonials from customers who say they felt more energetic after taking it. Therefore, Vitalax genuinely increases energy levels."

Question 10

"A restaurant critic argues: 'The best way to judge a restaurant is by how crowded it is. Bella Cucina is packed every single night, while the new bistro across the street is nearly empty. Bella Cucina must therefore be the better restaurant.'"

How to Review This Set (Don't Skip This)

Getting the answer right is only half the drill. For every question — including the ones you got right — do a blind review pass:

• Name the conclusion out loud. If you can't state it in one sentence, that's why you missed it.
• Name the assumption. The correct Weaken answer will always attack it. If you can articulate the assumption, the answer becomes obvious.
• Diagnose your wrong choice. Was it a Reverse? Out-of-scope? Too weak? Categorize the trap you fell for. Over time you'll notice a pattern — most people have one or two trap types they repeatedly fall for.
• Reread the winner and confirm the mechanism. Does it introduce an alternative cause? A counterexample? A missing consideration? Labeling the mechanism trains your prephrasing.

The goal isn't to memorize these ten questions — it's to internalize the moves so you recognize them instantly on a fresh stimulus.

Where to Go Next

Once these feel comfortable, graduate to timed sets of official questions on LSAC's LawHub, the authoritative source for real released material. Mix Weaken in with Strengthen and Assumption questions, since they all live in the same causal-and-assumption family and the LSAT loves to test whether you can tell the direction of the attack. If you're consistently missing the causal-flaw questions (like #1, #3, and #7 in this set), that's your highest-leverage area — most Weaken answers on the real test hinge on an alternative cause or a broken causal claim.