The USian 21 is quite atypical, most countries have a lower drinking age... 18 is far more standard.
Fair enough. It used to be 18 in some parts of the U.S., too, but that apparently encouraged a lot of 18- to 20-year-olds to sneak across the border and drink, after which they'd drive back across the border drunk, so...
Why not use 'Don't drink if you're underage.' instead of a number?
At what age you are underage? Different countries has different legal age of drinking, sex, etc. Putting number there is better should you're an immigrant to prevent accidental crime...true story.
GlpGirls Are Boozing It Up...Glp#1418 Girls Are Boozing It Up...SnatchGlp Glp GlpGlpDon't drink if you're underage.Nice drinkin' style...No morrre!Oh!?Now, c'mon...Oh? You gonna have a drink too?Hunh!? You wanna go!!?FoomI can't take any more!