Hi akreimerman1,
We refer to these questions as "Rule Substitution Questions."
They first appeared in 2009, and you typically get 1 of them per LG section. They are often the hardest question on the section, and the most important thing to remember is not to spend too much time on these questions (or any one question, for that matter). These questions are worth the same as any other question, so spending a significant amount of time on them (and therefore not completing other easier questions) is not a good strategy.
The basic idea of these questions is that the correct answer will provide a rule that you could swap into the game (i.e. substitute) for the rule mentioned in the question without changing the game in any way. In other words, the correct answer, when combined with the other remaining rules, will produce the
exact same setup/diagram/restrictions as the original game. Any answer that changes the game in
any way, such as allowing a variable to go somewhere that it wasn't originally allowed to go or preventing a variable from going somewhere that it originally was allowed to go, is incorrect.
There are a number of strategies to tackling these questions. Rather than try to provide a detailed answer here that could go on for many pages, I'll refer you to a few places where we cover this very topic in great detail.
Here's a link to a previous question about this question type along with information on where to find detailed information on how to tackle these questions in the lesson 7 homework of The PowerScore LSAT Course.
viewtopic.php?f=6&t=33020
I will only add that you can also find a thorough discussion of these questions in chapter 9 of "The Logic Games Bible."
