The last rule is to avoid intoxicants.

Why? The first-glance answer is that drunks cause all kinds of suffering. Drug addicts harm everyone near them over and over again. This is bad behavior, and we all know it. Yet, most of us are not alcoholics or drug addicts, but that doesn’t let us off the hook. Mind-altering actions of all kinds, including smoking, coffee, caffeine, and other stimulants are also prohibited. Why? They affect your state of mind, and Buddhism is all about the mind. Your world is created by your own perceptions and mindfulness. If you change the way your mind works by the use of stimulants or mind-altering drugs, you are harming your own chances for enlightenment. These chemicals are also often bad for your own physical health as well, and causing physical harm and suffering is bad, even if you are doing it to yourself.

Thich Nhat Hanh has a field day with this one:

Aware of the suffering caused by unmindful consumption, I vow to cultivate good health, both physical and mental, for myself, my family, and my society by practicing mindful eating, drinking and consuming. I vow to ingest only items that preserve peace, well-being and joy in my body, in my consciousness, and in the collective body and consciousness of my family and society. I am determined not to use alcohol or any other intoxicant or to ingest foods or other items that contain toxins, such as certain TV programs, magazines, books, films and conversations. I am aware that to damage my body or my consciousness with these poisons is to betray my ancestors, my parents, my society and future generations. I will work to transform violence, fear, anger and confusion in myself and in society by practicing a diet for myself and for society. I understand that a proper diet is crucial for self-transformation and for the transformation of society.

Yes, he tells us that TV shows, conversations, and magazines can be toxic as well. He also suggests that a proper diet can be good for all of society.

So there you have it, the five precepts of Buddhism. Get started on those right away, or at least start thinking about following them.