Actually, I had a look into this in the last few minutes and it turns out that Public Drunkenness is an offence, but look how it is defined:
From The Irish Statute Book[/url:2nmvhztx]
[quote:2nmvhztx]It shall be an offence for any person to be present in any public place while intoxicated to such an extent as would give rise to a reasonable apprehension that he might endanger himself or any other person in his vicinity.[/quote:2nmvhztx]
Basically, it's talking about being falling down drunk.