logic games can be intimidating but they're very learnable
when you first start preparing for the exam it can feel like there are countless
different types of games that can be thrown your way
however the truth is all of the games that have appeared in the modern era can
be defined in terms of just a few basic characteristics
seven in fact
my name is mike kim and i'm the author of the lsat trainer
i want to talk with you a little bit about the general design of all LSAT
Logic Games
and i also want to discuss the one skill that will most determine how well
you perform on test day
your ability to diagram
let's get started
the
well are
here's a sample game
there are four such games per logic games section
each game presents a scenario and set of rules the further define that scenario
then we will be asked
five to seven questions that test our understanding
of the situation that we've been given
we'll come back to this game in just a bit but first let's discuss the general design
of all lsat logic games
every game that has appeared in the modern era can be thought of in terms of
three main design issues
assignment
ordering
and grouping
that's assignment
ordering
and grouping
let's break this down
every game is about assigning
elements to positions
seven runners compete in a race or
six friends split up into two different cars
your diagram will always involve positions
and a list of elements
and most commonly
you will notate assignment rules by either placing elements into these positions
or crossing out the elements above or below them
about two thirds of all games relate these positions in some sort of order
imagine that the runners game tells us that they finished the race
one-at-a-time
and let's imagine that we are given a rule about f and g
what could they tell us?
they tell us that
f finishes ahead of g
or vice verse of course
or maybe that f finishes right before g
or that f finishes exactly
two spots ahead a g
or
maybe there's exactly one person that finishes between f_ and g_
but we don't know if f or g goes first
there are lots of different types of ordering rules
but they're all closely related to one another
about half of all games arrange elements into groups
like the different groupings of friends that will ride in various cars for example
we will generally represent grouping rules vertically
and mark that elements go together
or don't
by stacking them
once in a while
it also makes sense to use other notations
like this one on the right
so again assignment, ordering
and grouping
this trio represents the core of what all lsat games are about
and now we've got two categories of complications
a pair of design complications and a pair of rules complications
let's quickly discuss them
some games involves subsets
characteristics that further define the positions
the elements or both
we can notate subsets using lower case letters
imagine for example the for the runners game we're told that some of the runners
are men
and others are women
if we get a rule about a certain element being a man or woman or about a man or
woman finishing in a certain position
we can notate it like so
and some games involve numbers issues
these most typically appear
when the number of positions is left uncertain
or when the number of positions doesn't equal the number of elements
imagine for example the going back to the cars grouping game
each car can sit up to four
but there's six friends total
and we're not sure how they're going to be split up
if we have rules about which spaces get filled or not
we can notate those like so
finally some of the rules are complicated by being made
conditional or complex
some rules are conditional
that is is that it is instead of just telling us, they tell us that
if one thing is true
then another thing will be true here some examples of conditional rules
we'll always notate conditional relationships
using arrows
and finally
some rules are complex
they involve multiple components typically by using the words and
or or
here's some examples
complex rules can be intimidating
but they're also often very
very useful
let's use a simple example to illustrate why
imagine you had this game
and got this rule
notice that by itself this rule
helps dictate three of six assignments
half the board
and commonly when it's coupled with some of the other rules of the game
the complex rule be the most important one in terms of dictating
where elements can
and cannot go
here's some of the key points that we've discussed thus far
all lsat logic games are about assigning elements to positions
about two thirds of all games involve ordering and about half of all games involve
grouping
some games like the one about the play
involved both ordering and grouping
the design of certain games can be further complicated by subsets
and numbers issues
and rules can be complicated by being made conditional or complex
just seven issues for you to master
and if you can learn to think about all LSAT logic games in terms of these
seven conditions
it will put you in a great position to perform at your best on test day
now its return to the game we saw at the beginning of the video so we can discuss
the specific diagramming and problem solving strategies
please go ahead and cause the video if you'd like to try this on your own
before seeing the solution
i think it's always a good idea to read the scenario and the rules before you
start diagramming
this will help you figure out your priorities
and it'll tip you off
on the best way to lay out the game
in this case you get eight friends playing four matches of chess
in order and we can set up our base and list our elements like so
one thing i noticed in the initial read was that three of the rules involve g
so i'm going to think about and notate these rules first
and though this is a small step
i'll go ahead and notate the fourth rule right next to the first one
because I can see that those two are very closely related to one another
next i'll go on to the other rules and notate those as well
during the test I'd probably just write in the H I rule
but if you want to include but not both to make sure you remember that
of course you should do so
and finally
it's helpful to mark the elements that haven't been mentioned in any of the
rules
in addition to notating the rules i always want to do to other things during the
setup
one
look for inferences the things that we figure out by bringing the rules
together
some games have
big upfront inferences that are essential for us to and cover
and others
like this one don't
in this case probably the most interesting inferences are that G and M
can't play in the fourth game
and K can't play in the first or second
you can notate those but it's not essential
two i want to confirm that my notations are exactly correct
and i can do that by looking at each notation
saying to myself what it means and checking my understanding back against
the original text
okay now that we've done that
let's go ahead and use our diagram to answer the question
notice the question stem gives us new information in the form of a condition
every time a question gives you new information you should expect that
you'll be able to make inferences off of it
and that these inferences
will be what lead you to getting to the right answer
here were told that L plays in the third match
looking at the rules we can see that that also means
f must play in the third match
looking right above the f_ l_ rule
we can see that if g_ had played in the second match
F couldn't play in the third
that must mean
G doesn't play in the second match
G plays in the first match
And since G and M can't play one another
and both g and m
must go before k
M must play in the second match
and K must play in the fourth
we've got two open slots and j
and either H or I to fill them
let's go through that one more time
if L plays in the third match f does as well
we must place g
M and k
and G and M
must go before k
G can't go in two because F is in three
so G must go in one
M must go in two
and K must go in four
now let's look at the answers we're asked which answer cannot possibly be true
that means we need the one answer that must be false
we should expect that the work we've already done makes that answer obvious
there's no reason
a_b_c_or e have to be false
and d is the correct answer
there's no place for H and J to play one another
i hope that explanation is clear
for further discussion on some of the topics that we covered today including a
breakdown of recent lsat logic games based on these seven characteristics
please check out my website the lsat trainer dot com
if you're ready to get started studying using the trainer methods you can
purchase the book on amazon and hopefully in your local bookstore
we discussed at the beginning the lsat logic games are very learnable
i hope this video gave you the sense that that is indeed true
if you sat through this whole thing you must be very interested in getting
yourself a top score
thank you so much for watching i wish you the best and take care