This is an optional vow you can take. The main reason for the vow not to drink is because drinking alcohol can cause you to lose control and so to break any other vows you might have taken, or generally lead to disorderly conduct that may harm yourself or others. You don’t have to take this vow , or indeed any of them.

If you lead a reasonably ethical life - they are just a way of kind of reinforcing that. There’s a kind of extra force to it to have actually taken a vow, and do the same thing as you’d do if you didn’t take the vow. But on the other hand taking the vow and then breaking it wouldn’t be such a cool thing to do.

So, I’ve actually taken all the five precepts myself. Not killing ,stealing, lying, sexual misconduct or intoxicants. And it depends on your preceptor. You can’t just take the vow yourself, without a preceptor to take it from - who in turn received it from someone else back and back to the Buddha or so traditionally they think.

Of course you can just decide not to drink or to reduce the amount you take, but to take it as a Buddhist vow you need a preceptor. Who would explain the vows to you normally in a dharma talk before you take them.

Anyway so some might be more strict than others in how they teach them. I was told that it is okay to take a small amount in conditions where you are expected to. For instance at a wedding, it might be that you need to take a glass of wine just to participate in the happy occasion. That would be acceptable according to my preceptor. As the main thing is not to become inebriated to the extent that you do something to break the other vows, and that’s not too likely to have that effect.

And - there are Buddhist traditions where they actually use alcohol. Not other drugs, but alcohol has had a long connection with humans, and it’s like, there are traditions for working with it, and if used well then it can help with your practice. There actually are “mad yogis” who use alcohol as part of their spiritual practice. But there are also plenty of westerners who hear of this and think “oh great this means I can be drunk all the time and call it a spiritual practice”. But actually to do it as a spiritual practice you have to have a very clear mind and a teacher is probably essential to keep you on track. Far from being easy, it’s actually a practice that needs someone who is very strongly connected to the Buddhist path and very strongly grounded, got their feet firmly on the ground, clay between their toes kind of thing. Then they may be able to do this. And they tend to have short lives too, tend to be a bit reckless, do things that are motivated by a deep wisdom and compassion, so uninhibited that they don’t really think about their own safety.

That’s definitely not a path for everyone.

But a little alcohol, for social reasons, not drink driving, not inebriated to the extent that you start doing things that harm others and yourself without realizing what you are doing - that’s not against the Buddhist teachings at all. Even if you have taken the vow, it depends on the preceptor as how strict it is, as I said, some will say for instance that a bit of alcohol is okay in special occasions where you do it out of compassion because it is helping others to take part e.g. in a wedding ceremony to take part in toasting the happy couple, that sort of thing.

And if you haven’t taken the vow, definitely not.