Should a person never lie?

In Mahayana, the Lotus Sutra in specific, the issue of truth telling is complicated by Upaya. So in the case of teaching the Dharma, a Buddha himself might lie for if move the student forward towards enlightenment, or was a suitable thing to do for other unfathomable reasons as long as the end point was okay.

Anyhow, I find the five precepts sort of un-Buddhist--

1-- no killing- A more Buddhist precept would be cause no suffering.

2,3-- no lying, no stealing- These have to do with not upsetting the basic order of things, i.e. don't break the law and get the Sangha into trouble with the local government.

4- no sex. This is an organization thing, the Sangha wasn't set up for taking care of kids.

5- no alcohol. This is trying to solve an ancient and modern social illness by decree. It provides a foundation for throwing misbehavers out of the sangha, but

As such, I don't look to it for guidance on ethics.

You have to read the ancient and modern texts, get a feel for what the ancient monks were driving at and on those grounds, I think a better criteria is what choices create and lead to suffering and which don't.

Letting Nazis, mass murders, spree shooters, rabid dogs, the neighboring country hellbent on genocide kill creates suffering. Killing the aggressors to put an end to the suffering is okay and so is lying to them to thwart their goals.

If I had some time I'd say something about consequentialism and utilitarianism, (the principle that what matters is the outcomes and the greatest good for the greatest number), which to me appear to be similar to Buddhist ethics, but I'm out of time.

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.