In/Out Grouping | LSAT Logic Games

[@richardmiller779]

I was very confused about the wording with the first rule, but i think I have figured it out, "M and O are selected, unless N is selected." and i initially guessed that it'd mean "M and O not N", with its contrapositive being "N not M or not O". However after writing it down and really thinking about the wording I think I see where my error was, M and O are selected *UNLESS* N is selected. While in common day to day language this would imply that N being selected makes both M and O being selected impossible, however when taken very literally, N's selection just makes not M or not O both possible. In other words, N being selected doesn't negate the possibility of M and O, merely makes either/both not being selected a possibility. if my initial understanding with the bi conditional was intended, the LSAT would use the terminology "If and only if", not just "unless". While I now understand what the test was saying, it does seem a bit needlessly complicated and relies more on memorization of the LSAT's specific use of language as opposed to actually testing any logical thinking skills.

[@aleishaaxo14]

Rule #1 really kicked my ass LOL, it's so confusing. Anyone else feel the same?

[@MB-gd6be]

I thought it was me... definitely a methodology to getting down pat

[@noritrujillo2860]

The reason M and N can both be in it’s because N is the necessary condition. When you satisfy the Necessary condition the rule falls off, meaning M becomes a floater and it can be in or out.

[@georgetteantwi5979]

doesnt make sense

[@OliviaBrandt-k1i]

So from what I am gathering, regarding question 5, is that because the sufficient conditions only talk about what is OUT, then the rule will not trigger. If the sufficient conditions were talking about what pieces must be IN, then the rule would trigger because of the necessary condition, which HAS to be true. So I am focusing on the sufficient conditions and what they say, not the necessary condition as it is irrelevant here as the rule is talking about what is OUT. Hopefully this makes sense/is correct! Thinking out loud haha

[@kathrynblanco8389]

Thank you for posting this! I'm still a bit confused by the first rule though. Doesn't it also mean that if N is selected, than either M or O isn't (or both aren't) and that if M and O are selected, then N isn't, making it function like a "if and only if" rule? That is, is the rule saying "M and O are selected unless N is selected, in which case at least one of M and O is out" or is it really saying "M and O are selected unless N is selected, in which case M and O may or may not be selected"?

[@LSATLab]

Hi Kathryn, the rule is saying that if either M or O is out, then N must be in. M and O can both be in, they can both be out, one can be in, while the other is out, and vice-versa. However, if either M or O is out, then N is definitely in. The following are all acceptable scenarios under the first rule. IN OUT M, N O O, N M N M O M, O, N ---- M, O N Notice in the top three scenarios, either M, O, or both are out. All of those guarantee that N is in. In the bottom two scenarios, M and O are both in, so N can be in or out (the first rule simply does not apply).

[@matthewciejka4349]

I don’t understand how all three, NOM, can be selected. If N is selected, either M or O or both must be out, no?

[@katieanne497]

@Foolish Wisdom exactly we need answers

[@LSATLab]

​@@matthewciejka4349 , sorry we apparently don't get notifications from follow-up comments so I never saw this. I'm not sure where you got that the rule says, "If N is selected, M or O must be out". The rule says, "If N is out, M and O must be in" or by contrapositive, "If M or O is out, then N must be in" When NOM are all in, does that violate either of those rules? No. Neither rule is triggered by NOM being in. The rule only applies when N is out (which it isn't), or when M, O, or both are out (which they aren't). Putting M, N, or O in will never trigger this rule. You can't violate a conditional rule that doesn't apply to your situation (i.e., that isn't triggered).

[@LSATLab]

@Foolish Wisdom sorry we apparently don't get notifications from follow-up comments so I never saw this. All those scenarios I listed were legal. None violated rule 1. As you said, "M and O together are in, if N is out". Since the word 'if' shows us the trigger, let's write that in an easier to digest order: "If N is out, M and O must be in" or by contrapositive, "If M or O is out, then N must be in" Do either of those final two scenarios violate these rules? ...(in)........(out) M, O, N ---- M, O N No. For the first one, where NOM are in, neither rule is triggered. Rule 1 is never triggered by any of them being in. The rule only applies when N is out (which it isn't in that first scenario), or when M, O, or both are out (which they aren't, in that first scenario). As for the second one, it triggers the rule, "If N is out, M and O must be in" and it's obeying that rule.

[@gevonnafassett6778]

Totally confused by rule number one. I agree with what you WROTE...if M or O is NOT selected then N IS selected. However, you SAID if M or O is not selected, then N is NOT selected. Which is correct?

[@r.p.8906]

he misspoke at 4:15.

[@r.p.8906]

It's easier on my brain to write this way the first rule. "UNLESS N is selected" M and O are selected, equivalent to: [ no N] on the LEFT ==> M and O. Contra is then easy / [no M] or [no O] ==> N. The key is to remember that the word UNLESS, flips the equation and negates only the item that is after the word UNLESS. That's the only thing to remember because it's not " logical" and we will get confused if we don't flip right away. You went straight into the contrapositive and most got confused how you got there.

[@LSATLab]

That's great! You're both reorganizing the sentence to make it easier for you to process and using a process similar to one that works for a lot of people--to replace "unless" with "if not."

[@aspotsnick8412]

@@LSATLab but what is the difference that and makes in the M and O are selected, because she put or in her interpretation and its throwing me.

[@lamarcuusbuckner7156]

OMG Yes... That is how I learned the "Unless Rule". Flip the equation and negate the words after UNLESS...

[@beatsthattalk6690]

I don't agree with your first rule about crossing out m and o if n is selected. The rule states m and o ARE selected UNLESS n is selected. So if no N, then yes M and O

[@LSATLab]

It looks like you are in agreement, right? You think it should say ~N --> M and O and the contrapositive to your rule would be ~M or ~O --> N And the latter is how it's represented on screen. Those are two ways of saying the same thing, so we're both right?

[@beatsthattalk6690]

@@LSATLab I may be ignorant to how contra positives work. Sorry if this is the case.

[@LSATLab]

@@beatsthattalk6690 No worries. A contrapositive is just a valid way to re-write any conditional rule. GIVEN THE RULE: if X, then Y we know that X guarantees Y. So if Y is ever absent, that tells us, by contrapositive logic, that X must be absent. If an original rule is LEFT ---proves---> RIGHT then a contrapositive says, "if not right, then not left" "If you're in NYC, you're in USA" by contrapositive, "if you're not in USA, you're not in NYC" But then there's one more rule: "and" / "or" switch when you're contraposing. GIVEN: "If you're an NBA star, then you're making at least six figures AND you're athletic." CONTRAPOSITIVE: "If you're NOT making at least six figures OR you're NOT athletic, then you're not an NBA star"

[@beatsthattalk6690]

@@LSATLab thanks so much. I'm gonna reread this and get my head around it... my Issue I'm having is if it's if X then Y, I don't see that as if Y then X. I'm obviously overlooking something so I'm gonna get my head around this!!!! Thanks so much again for your time and thoughtful response- appreciate it!

[@LSATLab]

@@beatsthattalk6690 , correct when they give us "if X then Y", you should NEVER see that as "if Y, then X". We're saying you should see it as "if not Y, then not X". You should probably just check out our lesson on Conditional Logic: kzbin.info/www/bejne/oJann6yhhNemrbs

[@malissagill2452]

The first rule is really tripping me up. I see your explanation to legalpeach as "either M and O are selected or N is selected, or both." but the unless word in my head keeps saying if N is selected than both M & O together can't be selected. I'm not understanding how the three can be selected at the same time.

[@LSATLab]

That’s the reason the LSAT uses the word unless. The logical implication is counterintuitive. You need to build a process for translating an unless statement. Take the two terms connected by unless (lets call them M/O and N) and present them in if/then form but use the following format. If one of them is not true, then the other is true.

[@cassady8437]

Do you have a video explaining the negative to positive and positive to negative relationships between players?

[@LSATLab]

Not on KZbin, no. The gist of it is that when a conditional relationship has Opposite Charges (pos to neg, or neg to pos) it creates an "at-least" placeholder. For example, F --> ~H H --> ~F That rule means that F and H can never both be IN, since the positive of one leads to the negative of the other. If they "can't both be IN", then "at least one is OUT", and so if you want you can write a F/H+ placeholder in the OUT column. That "+" sign means "at-least". We're reminding ourselves that F and H can both be OUT. We're just signaling to our brain, "The OUT column will always have at least one of F and H". A negative to positive relationship, like ~J --> O ~O --> J means that J and O cannot both be OUT. Putting either of them out leads to the other being in. Since they "can't both be OUT", that means that "at least one is IN". And so we could write an O/J+ placeholder in the IN column. Let me know if you have questions about any of that.

[@perrierider-nicholson502]

@@LSATLab Hey! I have a subscription to LSAT lab. What videos on your site explain negative to positive and positive to negative relationships between players? Thanks!

[@juliacho4373]

Thank you for the video. They are super helpful! For G1 Q2, can you elaborate a little more on why it has to be from negative to positive? And if it's at least one, can't both T and L be selected?

[@LSATLab]

Hi JC, it could be the case that both T and L are selected, but it also could be the case that neither T nor L is selected. Since it's possible that neither is selected, it doesn't have to be true that at least one of T and L are selected. The reason negative to positive is the desired relationship, is that the question is looking for at least one of the pair to be selected. You can think of a rule that moves from negative to positive as saying that at least one of them is selected. A negative to positive rule guarantees that if either of them is out, the other is in.

[@greysonchristophercassidy1710]

I notice that the Logic Questions are each subject to individual methods for selecting the correct answer . For example ' Tree Ordering ' - or as it relates to this particular question - In / Out Grouping . The first question discussed here is difficult less due to it being a ' Logic Game Question' and primarily due to wording which is vague . Selected / Unselected - M O P / T L N . The line of questioning that follows , and how to correctly visualize a correlation between them and the correct answers is , once again , vague . Other ' Logic Game ' questions - although of equal or greater difficulty have a greater clarity of understanding and continuity between the initial ' Stimulus ' and the following ' Line of Questions ' . #GreysonCassidy 🇺🇸 Temporary Staffing Agencies

[@roseb2105]

I thinks so to I diid not understand the first rule i intrepreted it as m and o are always present unless n is present

[@VinesGrapesAndWines]

what i infer from the first condition is that both (M and O) are selected, unless N is selected, in which case if N is selected then M and O are not selected. the word used is "AND" which binds them together.

[@LSATLab]

If you read through the comments on this video, you'll see that almost everyone asks about this rule (and we've provided lots of follow-up examples and clarification). The short version is that people confuse themselves if they try to internalize the meaning of the rule. Just be very precise about symbolizing it, and you can't go wrong. Whenever you see "unless" in a conditional rule, you can replace that with "if-not". Saying "X happens unless Y happens" is the same as saying "X happens if Y not happens", which would be ~Y --> X Saying "unless X happens, Y happens" is the same as saying "if X not happens, then Y happens", which would look like ~X --> Y This rule says M and O are selected unless N is selected, so we know "If N not selected, M and O are selected". ~N --> M and O The contrapositive to that rule is ~M or ~O --> N The rule is only triggered by stuff being put in the OUT column. Putting, N, M, or O into the IN column doesn't trigger these rules. These rules have nothing to say about those circumstances. Say they're all IN IN: M, N, O ... OUT: other people The rule says, "If N is out, then M and O are selected" Okay, well N isn't out, so this rule has no bearing on the scenario we wrote. The contrapositive says, "If M or O is out, then N is selected". Cool, well neither M nor O is out in our scenario, so again this rule has no bearing.

[@svensnation2122]

I think you made an error at 16:43. You said that LMNO can make a pair, however N can't be selected if M and O are selected. The answer was still right though, because you can have TMNL.

[@LSATLab]

Hey, thanks for asking about the potential error. But it's okay for M, N, and O to all be selected. The first rule (which is the subject of tons discussion on this comment thread, if you want to read more about it) is ~N --> M and O ~M or ~O --> N When M, N, or O are IN, it doesn't trigger anything. That rule is only triggered by putting any of them OUT.

[@devanshisharma2580]

14:30 how they both can be out ?

[@InvictusWarrior]

I am confused about the role of P in the chain especially in question 2. Can we infer that P -> /T ? If not, what is the correct contrapositive of the entire sequencing chain? Thanks.

[@LSATLab]

Yes, we can infer that P --> /T. I can't write the contrapositive chain in this typing environment because I can't do a fork in the road, but reading via the contrapositive, when P is in, you get this list of chain reactions. P --> /L, /N, M, O, /T The relationship between P and T is that they can't both be IN. P --> /T T --> /P Since they can't both be IN, then at least one is always OUT (we could add a P/T+ placeholder to the OUT column if we so chose). But they can both be OUT. Their conditional relationship doesn't mean that one is IN, one is OUT. We could have this scenario: In: N, L Out: P, M, O, T That wouldn't break any rules, and it proves that (B), (D), and (E) are all wrong. Evidently, we see from this scenario, it's NOT the case that at least one of (M,P), (O,P), or (T,P) must be in. For all three of those pairings, this scenario proves that they could both be OUT.

[@perrierider-nicholson502]

What video on your site explains negative to positive and positive to negative relationships between players? TYIA

[@LSATLab]

Hey, this is prob not the best question for KZbin. Since you said in another msg that you're on the platform, can you just send us a chat through that blue bubble in the bottom right of the homepage? There's not a specific video on it, but if you search for games with the tag "Powerful Placeholders", those explanations usually involve discussions of those Opposite Charge rules And there are some Study Activities on In/Out Games that discuss the opposite charge stuff. I can give you links / add stuff to your study plan, if you msg through the site.

[@casanovathamarauder]

Thanks for this!

[@Padraic54]

I keep getting tripped up by the wording. "M and O are selected, unless N is selected" made me think that neither M or O would be selected if N was present.

[@Padraic54]

Also, I didn't expect L M N O to be a grouping under the rule "M and O are selected, unless N is selected".

[@LSATLab]

@@Padraic54 the rule that M and O are selected, unless N is selected is tough because the "unless" is conceptually very tough for most people. I'd recommend looking at "unless statements" in the following way. If either condition is not true, the other condition must be true. So if it's not the case that M and O are both selected, then it must be the case that N is selected. Or if N is not selected, then it must be the case that both M and O are selected.

[@Padraic54]

Yeah, I just have to program myself. I'm enjoying your videos. I've watched all five on logic games.

[@legalpeach7725]

I still can’t understand how M and O aren’t coupled together. Reading that rule, how should I think about it to understand that one can be paired with N, but not both?

[@prolificbeats8237]

LSAT Lab why wouldn’t N cancel out M and/or O if it is selected. It sounds contradictory to say M and O are selected unless N is selected and then go and select N to group with M,O, and L. Don’t understand how that’s not contradictory and confusing

[@dianachang7182]

VERY helpful!!! Thank you

[@aspotsnick8412]

On the question with the maximum, doesn't LMNO being selected violate the first rule, M & O are selected, unless N is selected

[@LSATLab]

No, that rule says "If N isn't selected, then both M and O are selected". It doesn't have any bearing on scenarios where N *is* selected. Symbolically it looks like this. ~N --> M and O ~M or ~O --> N In a scenario where LMNO are all in, neither one of those triggers is applicable. The first line says, "If N is out" ... but it's not, so this rule doesn't apply. The second line says "If M or O is out" ... but they're not, so this rule doesn't apply. (tons of people have commented on how confusing that first rule is, so if you want to read some more discussion of it, just expand some of the past comments.)

[@amandas2653]

I know a lot of people have asked about this, but I don't understand how M, O, and N can all be selected. The rule indicates that UNLESS N is selected, M&O will be selected. I took this to mean either M or O must be out for N to be in. Would it be more accurate to interpret the rule as- M&O must both be selected, unless N is selected, in which case the previous statement does not apply. So if N is selected, there is no obligation to include/exclude either M or O. Is the problem with my initial analysis that I took M+O to dictate N, while it is actually the absence of N that dictates M+O?

[@LSATLab]

Yeah, you nailed it. It sounds more like what it means when you re-order the sentence to say "M and O will be selected unless N is selected". With conditional logic indicator words (if, when, the only, only, only if, unless, etc.) it doesn't make any difference where they appear in the sentence. You get the same conditional statement either way. "X happens only if Y happens" is the same as "Only if Y happens does X happen" (X --> Y). When you say it like, "M and O will be selected, unless N is selected", you can hear it like "the default thing is M and O in. The only thing that could avert that is N being in. So when N is selected, M or O or both could be out, but otherwise M and O will always be in." It's sort of like saying, "Unless we take big action on climate change now, there will be superstorms and climate refugees in the future". That's saying that "superstorms and climate refugees" are the default thing that's happening. Only taking big action on climate change could create a possibility where superstorms, climate refugees, or both fail to happen. But even if there is big action on climate change, those other two things could still happen. (Why did I choose the most depressing example possible?)

[@colinpatrican6451]

This explanation is still confusing as all hell. You said the only thing that could affect M and O from being in - is if N is also in. So how is it possible that if N is in, both M and O are both in. N is in, that is the one thing that can affect M and O from being out. So how can all three be in?

[@LSATLab]

@@colinpatrican6451 right, the only thing that COULD affect M and O from being in is if N is in. But that doesn't mean that when N is in it necessarily DOES affect M and O being in. It allows them the freedom to be out, but it doesn't mandate that they're out. "The only thing that COULD prevent superstorms and climate refugees is big governmental action on climate change." Does that mean that if there is governmental action on climate change, you're definitely avoiding superstorms and climate refugees? Nope. We could say "You're getting rejected from Yale UNLESS you have a great GPA and and great LSAT score". Does that mean that all 3 of those could never coexist? Or is it possible that you have a great GPA, you have a great LSAT, and you get rejected from Yale? Naturally, and tragically, that's still possible. There's nothing about the form "X happens unless Y and Z happen" that prevents all three from happening at the same time. We could do these all night: "You're going to get dumped by Alexis unless you treat her well and remember to buy her a gift on her birthday". Does that mean that if you treat her well and remember to buy her a gift on her birthday, that you'll never get dumped by Alexis? Or is it possible that you treat her well, remember to buy her a bday gift, and she still dumps you? She still might dump you. This rule is saying "the only way that you COULD stay with her is if you treat her well and get her a bday gift", but that doesn't mean that treating her well and getting her a bday gift guarantees you'll stay together. p.s. even though I'm trying to give conversational examples for people who are trying to understand this conversationally, let me not bury the lede: 98% of the time, it's easier to deal with conditional logic on LSAT mechanically than intuitively. One mechanical trick we can do with UNLESS is just take either half of the sentence, negate it, and put it on the left side. So if I'm given M and O are selected unless N is selected, I'm just thinking "Let's take the idea 'N is selected', negate it, and put it on the left of the arrow." ~N --> M and O and then by contrapositive ~M or ~O --> N Whenever we have a conditional statement, let's use a real world example like NYC --> USA ~USA --> ~NYC It creates three possible worlds: 1. topline (you're in NYC and you're in USA) 2. bottomline (you're not in NYC, and you're not in the USA) 3. the right sides (you're in the USA but not in NYC) So when you look at this rule ~N --> M and O ~M or ~O --> N You can have these three worlds 1. N is out, M and O are in 2. M, O, or both are out, and N is in 3. M, O, and N are all in

[@colinpatrican6451]

@@LSATLab First, thank you for your response and explanation I truly appreciate it. However, maybe I'm a little thrown because this is the first example of a rule I've encountered where it appears to have three separate outcomes all of which seemingly make the first rule pointless by itself (without inferences drawn from connected rules). On one hand, you have the interpretation of the way the rule is stated ~N--> M and O and it's contrapositive ~M or ~O -->N... then forget both of them they can all be IN and they can all be OUT forget the rules, what do they matter? See where I'm coming from? I've been practicing for about 7 months for the LSAT and this is the first logic game that's had this unusual wording that could be interpreted with a more abstract approach rather than logical.

[@LSATLab]

​@@colinpatrican6451 All conditional rules (not bi-conditional) have 3 possible worlds. But, trust me, I taught LSAT for many years before I actually articulated that observation. The 3rd world that we are overlooking is when a rule doesn't tell us to do anything. You know from your LSAT experience how to handle "unless" and you can successfully translate that rule into ~N --> M and O ~M or ~O --> N Rules with opposite charges (negative on one side / positive on the other) tend to give us the misconception of mutual exclusivity. But just put M, O, and N into the IN column and see whether it breaks those rules. IN: M, O, N .... OUT: other dudes We have a rule that says, "If N is out ... " But N isn't out, so that rule doesn't apply, and hence we can't be breaking it. We have a rule that says "If M or O is out ..." But they're not out, so that rule doesn't apply, and hence we can't be breaking it. The more common version of a rule like this is when we're doing In/Out and a get a rule like "P and T cannot both be selected". Does that mean that one is IN and one is OUT? No, but when we see the opposite charges, that's what people often think: P --> ~T T --> ~P P and T can both be OUT. The rules don't have any problem with that. The rule said they can't both be selected, but they could both be rejected. The world where T and P are both out is that 3rd world where both right sides are true. The converse of that rule would look more like the one we're grappling with. ~P --> T ~T --> P This rule means they can't both be rejected. But they could both be IN. Ain't nuttin' wrong wit dat.

[@r.p.8906]

how do you know in question 2 that it needs to go from out to in? the question does not say that. At least one is selected means 1 or more than one. Is this game a LSAT game?

[@LSATLab]

No, LSAC only lets companies use a few specific tests for any free online lessons (it was 65, 71, and June 2007, although they recently tinkered with that). There weren't any In/Out games in those available tests, so we had to write one in order to put a lesson on KZbin (behind our paywall, where students all have LawHub accounts, we're allowed to use whatever examples we want). Throughout IN/OUT games we end up translating back and forth between "Can't both be IN = at least one is OUT" and between "Can't both be OUT = at least one is IN". So when a question is saying, "Which of the following is a pair, at least one of whom must be selected", then the one correct answer features a pair where at least one must be IN (they can't both be OUT). Meanwhile, the four wrong answers have a pair where it isn't the case that at least one must be IN (they *could* both be OUT). If we're looking for a pair of people who can't both be IN, then we look for a rule that goes from positive to negative ("Putting X in forces Y out, so they can't both be IN"). If we're looking for a pair of people who can't both be OUT, then we look for a rule that goes from negative to positive ("Putting X out forces Y in, so they can't both be OUT")

[@ryansaxton4921]

N is a third wheel in the relationship with M and O. If O is not available then M will take N. Same with O if M is unavailable.

[@abandonallhope.1040]

Anyway you could go over problems from PT 91?

[@LSATLab]

We do that on our website, but we're only allowed to discuss those problems behind a paywall. LSAC has certain tests that test prep companies are allowed to use for "marketing" purposes, so that's all that's supposed to be allowed on KZbin. It used to only be June 2007, test 65, and test 71. They changed it this summer to now NOT include test 71 and to include test 73 instead. But nothing from the 80's or 90's is allowed, unless you're behind a paywall where students have an active LawHub account.

[@4shanna]

This was so helpful thank you

[@jasonlou2013S]

Thank you again!

[@roseb2105]

i am confused about rule 1 I thought if both m and o guarentee no n then if there would be an n then neither of them chould be present so in other words there cannot be an mn no or mon is that correct?

[@StuckeyFamily6]

Q2: how come E is not an option? How did you know to go from negative to positive?

[@LSATLab]

Hey, Keisha. You would only know that if you're a super nerd about In/Out games (meaning: it's not at all obvious by just reading the question) The gist of it is that when a conditional relationship has Opposite Charges (pos to neg, or neg to pos) it creates an "at-least" placeholder. For example, F --> ~H H --> ~F That rule means that F and H can never both be IN, since the positive of one leads to the negative of the other. If they "can't both be IN", then "at least one is OUT", and so if you want you can write a F/H+ placeholder in the OUT column. That "+" sign means "at-least". We're reminding ourselves that F and H can both be OUT. We're just signaling to our brain, "The OUT column will always have at least one of F and H". But for our purposes what's important is understanding how those are two different ways of saying the same thing: "if X and Y can't both be IN", then "at least one of them is OUT". A negative to positive relationship, like ~J --> O ~O --> J means that J and O cannot both be OUT. Putting either of them out leads to the other being in. Since they "can't both be OUT", that means that "at least one is IN". And so we could write an O/J+ placeholder in the IN column. Q2 is asking us about a pair of stones for which "at least one is IN", which is another way of asking, "which pair of stones can't both be OUT". Whenever characters have a negative to positive relationship, it will mean they can't both be OUT, which means at least one is IN. The reason we know (E) is wrong is that we can write a legal scenario like this that would disprove (E). in: N L, out: M, O, T, P That legal scenario proves that it doesn't HAVE to be the case that at least one of T and P are selected. We just saw a scenario where neither of them are selected.

[@simonkaslizek9499]

For G1 Q3, how come P does not HAVE to be selected if L is out? How come L out doesn’t have to result in P In?

[@LSATLab]

The original rule says "L is selected only if P is not" If we write that as a conditional rule, we would think to ourselves, "I know that *only if* always introduces something required; it always introduces the necessary condition. So the necessary condition is that 'P is not selected'." Thus the rule would look like this: L --> ~P and the contrapositive P --> ~L On Q3, we're told that L is out. In other words, we're told ~L ~L isn't a trigger. If we looked at "P --> ~L" and thought that L being out means that P is in, we'd be committing an illegal reversal. If we looked at "L --> ~P" and thought "if L isn't selected, then P is selected", we'd be committing an illegal negation. Conversationally, let's say you have two friends, Mark and Regina, who dated for years but recently broke up and things are awkward between them. You're trying to figure out who's invited to your wedding so you're thinking, "Mark can come only if Regina does not come". You don't want them both to be there. By contrapositive, "Regina can come only if Mark is not there". But Q3 is saying, "If Mark isn't at the wedding, what do we know." We don't know anything. We might be tempted to say that Regina WILL be at the wedding, but nobody said you had to invite either one of these fools. We only said you can't invite both of them. One of them can attend only if the other one doesn't. But it's also allowable for neither of them to attend.

[@BowWowluva07]

in question 2, how do you determine that it needs to go from neg-pos and not pos-neg?

[@LSATLab]

Positive to negative rules mean two characters "Can't Both Be IN". If we have this rule (and contrapositive): P --> ~T T --> ~P Then P and T can't both be in. (but they could both be out). So if we were asked a question like, "Which of the following is a pair of people who cannot both be selected", we would think, "Okay, two people can't both be IN if putting one of them IN sends the other one OUT. So I'll look for a pos to neg relationship". If we have this rule: ~R --> M ~M --> R That means they can't both be OUT (but they could be IN). If we were asked a question like, "Which of the following is a pair of people who cannot both be rejected", then we would think, "Okay, two people can't both be OUT if putting one of them OUT triggers the other person IN. So I'll look for a neg to pos relationship". And LSAT, rather than asking "which is pair that can't both be rejected" says the same thing a different way, "which is a pair at least one of whom must be selected". For the four wrong answers, "Neither person needs to be selected. They could both be out." For the correct answer, "At least one must be selected. They can't both be out." Let me know if any of that was confusing.

[@BowWowluva07]

@@LSATLab Not confusing, however, I do mean from the initial question, "at least one," does this verbiage mean we are looking only for neg-pos or could "at least one" also mean pos-neg? Also, why couldn't it be the case that "can't both be in" become the same as "at least one" because in that scenario, if both are in, then it is true that at least one is in. Does that make sense?

[@LSATLab]

@@BowWowluva07 , the way the question was worded you only care about neg-pos. Asking "for which of the following pairs must it be the case that at least one is selected" is the same as asking "which of these pairs cannot both be OUT at the same time". That's why we only care about neg -> pos. Your follow up question, I think, is losing track of the fact that this is still a MUST BE TRUE question. We don't care if the answers "could" happen, so we won't be doing any testing to see, "Is it cool if at least one of these is in?" On Must Be True, we only care about whether an answer could fail to happen, so we only bother testing whether we can defy an answer choice. For the wrong answers, "it doesn't HAVE to be true that at least one is selected. They can both be OUT." But for the correct answer, 'It DOES have to be true that at least one is IN. They *cannot* both be OUT (because they have a neg -> pos relationship)."

[@BowWowluva07]

@@LSATLab Got it! That makes sense. Thank you so much for getting back to me.

[@brionahall7333]

Im confused by this entire method

[@legalpeach7725]

Are N and L conditional? Could it be reversed so that if L is selected, N is selected? Or is just if N if selected, L is selected?

[@branholo5814]

How would you know if you need multiple game boards? I'm having trouble figuring out when I need just one board or multiple boards

[@LSATLab]

You never *need* multiple game boards, so it's always an okay decision to just head to the questions. But if you see a rule that seems important / relevant to other rules, and it only has 2 or 3 options, then it can be worthwhile to start each of those game boards so that you can see whether other dominos fall (if not, no worries). Most of the time, we're creating multiple boards because there's a Block/Chunk rule (these two people are stuck together) and that block could only go in 2 or 3 spaces, and once you commit it to one of those spaces, it will cause something else to happen. Making multiple boards for an In/Out game is pretty rare. Your default mentality for this game type should be that you probably will *not* be building multiple boards.

[@branholo5814]

@@LSATLab Thank you!

[@loopymomy2532]

Hi can you do videos on technique for logical reasoning? Like the stem “which one of the following comparisons is utilized by the argument?” Thanks! Keep doing reading Comp! It’s the hardest section on the lsat lmao 😭

[@LSATLab]

Hey, we have lots of videos on LR up on KZbin. Have you already checked those out? The question stem you referred to "which comparison is utilized by the argument" is a total one-off. That question you're thinking of is the only time I can remember them ever asking that. Also, LSAC only allows companies to use questions from 3 specific tests, so we can't make explanation videos for specific problems outside of those three tests. The closest videos that would apply to a question like that would be our video on Comparisons: kzbin.info/www/bejne/Z6WQeH98gqqCrc0 or on Method: kzbin.info/www/bejne/bJCvpXuNh7eSiM0

[@loopymomy2532]

@@LSATLab thanks I watched the method one already! I will watch the comparison one later. I’m working on reading comprehension at the moment.

[@ianattle4747]

I am a senior in high school and I am studying for this so I get it all memorized early on. Do you all got any tips

[@LSATLab]

The Games section is disappearing after the June 2024 test. So if you're not planning to take the LSAT in April or June of 2024, then there's no reason to study Logic Games at all (unless you enjoy them on their own).

[@ianattle4747]

@@LSATLab they are still skills you got to know to be an attorney. I am still going to study them. What are they going to replace them with? Logic is still something every attorney needs to know. I will still plan on reading comprehension and logic argumentation

[@LSATLab]

@@ianattle4747 instead of the current format (1 Logical Reasoning, 1 Reading Comp, 1 Logic Games), there will be 2 Logical Reasoning sections and 1 Reading Comp section.

[@ianattle4747]

@@LSATLab that's interesting it's still good to know logic games anyhow

[@deborahchitester9772]

watching all this integrating just tryng to figure out all relevant times we need to apply contrapositive concept

[@legalpeach7725]

I keep commenting sorry but I feel like the word “and” between M and O is what is tripping me up. Is it that it’s saying “M AND O are in unless N is in” but its NOT saying that they cannot be paired individually with N? And the only answer that rules this out is D. Sorry if this is utterly confusing, it’s the only way my brain can make sense of it - if that’s decently correct

[@LSATLab]

One way to understand unless relationships is that either M and O are selected or N is selected, or both. You are right, its NOT saying that they cannot be paired individually with N.

[@SLTR7]

You contradict yourself at parts or you're making it very confusing for a lot of us. How can L,M, and O all be together. Or M and O be together alone? Doesn't that make the first rule incorrect??

[@LSATLab]

Happy to help. The first rule is a tough one to follow because of the use of the word "unless." The rule does not say anything about what happens if M and O are in. It only says what happens if either M or O are out. If either are out, then N is in. Here's the formula I personally use with "unless." What follows unless becomes the necessary condition, while the other part of the relationship is negated and becomes the sufficient condition. So for example, if you had the statement: A is selected, unless B is selected. Take the B after unless and put it on the right side of the arrow. ____ ---> B Then take the other term and negate it before putting on the left side of the arrow. ~A ---> B This rule says nothing about what happens if A is selected. But it does say that if A is not selected, then B must be selected.

[@SLTR7]

@@LSATLab Thank you for the thorough response, I really appreciate it. I was sitting for about 30 minutes trying to understand why L,M, and O were all allowed to be in.

[@dadequalcustody8350]

Question #2 did not make sense to me at all.

[@WhyDontWeNJNation]

I'm so lost on his explanation for question 2

[@puneetantaal9272]

I have searched and cannot find one instance of an "unless rule" like the one in this problem, and seeing as 99% of the comments are people being confused, why don't you make an updated video for this concept instead of complicating it with an extremely rare example that is not tested. Just seeing as this is the top video when you type in "LSAT logic games grouping", I think you should go back and remake the video at this point just so people can see these rules illustrated in a better way. Whether or not your right, the fact that for an instructional video you're having to individually re-explain the video to every comment should show that this video is not doing what was intended.

[@bomontiel3148]

The interpretation of the first rule is wrong. You turned it into an “or” and it clearly states “and”. M “AND” O are selected, unless N is selected. M and N can not be selected, neither can O and N. You even left answer D in as a valid answer when reviewing the first rule. And that even violates your arbitrary “or” condition you made up. All three can not be selected.

[@LSATLab]

It's not wrong, but it's certainly the most confusing part of the video by far (check out other comments). Mechanically, you can always replace the word "unless" with the phrase "if it is not the case that". So the rule that M and N are selected unless N is selected could be re-written: "If it's not the case that N is selected, then M and O are selected". ~N --> M and O That rule tells us what has to happen when N is out. It doesn't tell us anything about what has to happen when N is in. When N is in, it doesn't matter (according to this rule) what we do with M and O. When you write a contrapositive, you reverse and negate all the terms. Part of negating all the terms is switching 'and' for 'or' (or vice versa). If we're given A --> B or C then the contrapositive is ~B and ~C --> ~A Since this first rule says ~N --> M and O the contrapositive is ~M or ~O --> N

[@bomontiel3148]

So is that to say then that M and O can still be selected if N is selected? Or one but not both?

[@LSATLab]

​@@bomontiel3148 , all 3 of them can be IN at the same time. This is a weird dark example (first that came to mind), but say we said, "You must be frugal and kind, unless you're terminally ill". Does that rule mean that if you're terminally ill, you're NOT allowed to be frugal and kind? Of course not. You can be terminally ill, frugal, and kind. You can think of the trigger here as the DEFAULT, and the only possible way the default would not be true would be if the outcome were false. The DEFAULT is "frugal and kind". The only time you're allowed to deviate from that is if you're terminally ill. But that doesn't mean you have to deviate from that if you're terminally ill. In the rule, "M and O are selected, unless N is selected", the DEFAULT is that M and O are in. The only time we're allowed to deviate from that is if N is selected. But when N is selected we don't *have* to deviate from that. We can still keep M and O in if we want to. With any conditional rule, f.e. NYC --> USA ~USA --> ~NYC there are three possible worlds 1. the top line is happening (someone is in NYC and also in the USA) 2. the bottom line is happening (someone is not in NYC and not in the USA) 3. the two right sides are happening (someone is in the USA but not in NYC) So if we look at the rule, ~N --> M and O ~M or ~O --> N We could have these three worlds 1. N is out, M and O are in 2. at least one of M/O is out, and N is in 3. M, O, N are all in.

[@bomontiel3148]

Haha the candid example is appreciated. The response is impressive and was not expected but definitely appreciated. This thread should help many. I guess the key also being “sufficient but not necessary”. I’ve spent the entire day learning logic and this now makes sense. Thank you.

[@liamtalks6330]

i fawnd u dada

[@willsharpe1893]

Rule 1 is about the dumbest thing I've seen in a logic game

[@YallNeed2GetaGripPodcast]

This is not a good explanation for in and out logic games !!! Anyone who is inexperienced with logic games should find another video as this will delay your learning process instead of help it!!! 4:17