user6921: If someone would hide from the Nazis and then the Nazis came and asked me if I'm hiding a Jew - should I say "yes" or "no"?  
When is it ok to lie? 

user-1: If serious with the practice, if having real faith in the Buddha, or even insight, YES: never ever lie and become more innovative in complicated seeming cases. There is no reason to ly. If starting reasoning all precepts have no use at all, but actually to simply cut of the danger of reasoning (opposition of the defilements) is the Sīlas purpose.
In regard of this merely polemic question, Breath had posted, here some general and specific answers to help those still having the need of reasoning in regard of strict precepts for a strict aim: release.

from a letter of Ven. Thanissaro in response of the undermining undertaking by Bhikkhu Bodhi in regard of justifying the break of precepts for "higher" seeming purposes:
5) The Buddha never said that the intention underlying the precepts was something as vague as “reducing harm and suffering” or “the preservation of life.” Those principles can be used to justify all sorts of evil. The only general principle he expressed for ideal actions is one that he expressed both negatively—that such actions not afflict oneself or afflict others (see Majjhima 61)—and positively: that they benefit oneself and benefit others (Anguttara 4:99). As this latter sutta makes clear, you benefit yourself by abiding by the precepts. You benefit others by encouraging them to abide by the precepts. When you try to get others to believe that there are times when it’s morally laudable to kill (equal in regard of the other 4 precepts), you’re working for their affliction.

Essays explaining the function of Sīlas: 
Virtue without Attachment
Justice vs. Skillfulness
Monks and lay teacher, seeking favor under their target followers and for a broad audience, jet still worldling, not full faith in the Three Gems come constantly up with ways to pull the Dhamma into their own tendency rather to let Dhamma form one fit for liberation.
Note that doubt into the absoluteness of the simple precepts is a clear sign for not having gained path or fruit on the Noble Eightfold Path.
The only way to really find out the impact of practicing the precepts like they are, simple, is to put it by one self into action, based on convidence at first place.

user254: In Good Question Good Answer, in the chapter about the five precepts,  Ven. S. Dhammika wrote,

QUESTION: If you were sitting in a park and a terrified man ran past you and then a few minutes later another man carrying a knife ran up to you and asked you if you had seen which way the first man had gone, would you tell him the truth or would you lie to him?
ANSWER: If I had good reason to suspect that the second man was going to do serious harm to the first I would, as an intelligent caring Buddhist, have no hesitation in lying. We said before that one of the factors determining whether a deed is good or bad is intention. The intention to save a life is many times more positive than telling a lie is negative in circumstances such as these. If lying, drinking, or even stealing meant that I saved a life I should do it. I can always make amends for breaking these, but I can never bring a life back once it is gone. However, as I said before, please do not take this as a license to break the Precepts whenever it is convenient. The Precepts should be practiced with great care and only infringed in extreme cases.


6921: <p>If someone would hide from the Nazis and then the Nazis came and asked me if I'm hiding a Jew - should I say "yes" or "no"?  </p>

<p>When is it ok to lie? </p>
 -1: <p>If serious with the practice, if having real faith in the Buddha, or even insight, <strong>YES: never ever lie</strong> and become more innovative in complicated seeming cases. There is no reason to ly. If starting reasoning all precepts have no use at all, but actually to simply cut of the danger of reasoning (opposition of the defilements) is the Sīlas purpose.
In regard of this merely polemic question, Breath had posted, here some general and specific answers to help those still having the need of reasoning in regard of strict precepts for a strict aim: release.</p>

<blockquote>
  <p><em>from a letter of Ven. Thanissaro in response of the undermining undertaking by Bhikkhu Bodhi in regard of justifying the break of precepts for "higher" seeming purposes:</em></p>
  
  <p>5) The Buddha never said that the intention underlying the precepts was something as vague as “reducing harm and suffering” or “the preservation of life.” Those principles can be used to justify all sorts of evil. The only general principle he expressed for ideal actions is one that he expressed both negatively—that such actions not afflict oneself or afflict others (see Majjhima 61)—and positively: that they benefit oneself and benefit others (Anguttara 4:99). As this latter sutta makes clear, you benefit yourself by abiding by the precepts. You benefit others by encouraging them to abide by the precepts. When you try to get others to believe that there are times when it’s morally laudable to kill (equal in regard of the other 4 precepts), you’re working for their affliction.</p>
</blockquote>

<p><em>Essays explaining the function of Sīlas:</em> </p>

<p><a href="http://zugangzureinsicht.org/html/lib/authors/thanissaro/beyond_en.html#ch6" rel="nofollow noreferrer">Virtue without Attachment</a></p>

<p><a href="http://zugangzureinsicht.org/html/lib/authors/thanissaro/justicevsskill_en.html" rel="nofollow noreferrer">Justice vs. Skillfulness</a></p>

<p>Monks and lay teacher, seeking favor under their target followers and for a broad audience, jet still worldling, not full faith in the Three Gems come constantly up with ways to pull the Dhamma into their own tendency rather to let Dhamma form one fit for liberation.</p>

<p>Note that doubt into the absoluteness of the simple precepts is a clear sign for not having gained path or fruit on the Noble Eightfold Path.</p>

<p>The only way to really find out the impact of practicing the precepts like they are, simple, is to put it by one self into action, based on convidence at first place.</p>
 254: <p>In <em><a href="http://www.buddhanet.net/pdf_file/gqga-5ed.pdf" rel="noreferrer">Good Question Good Answer</a></em>, in the chapter about the five precepts,  Ven. S. Dhammika wrote,</p>
<blockquote>
<p><strong>QUESTION:</strong> If you were sitting in a park and a terrified man ran past you and then a few minutes later another man carrying a knife ran up to you and asked you if you had seen which way the first man had gone, would you tell him the truth or would you lie to him?</p>
<p><strong>ANSWER:</strong> If I had good reason to suspect that the second man was going to do serious harm to the first I would, as an intelligent caring Buddhist, have no hesitation in lying. We said before that one of the factors determining whether a deed is good or bad is intention. The intention to save a life is many times more positive than telling a lie is negative in circumstances such as these. If lying, drinking, or even stealing meant that I saved a life I should do it. I can always make amends for breaking these, but I can never bring a life back once it is gone. However, as I said before, please do not take this as a license to break the Precepts whenever it is convenient. The Precepts should be practiced with great care and only infringed in extreme cases.</p>
</blockquote>
