Certification
- Argentina:16
- Australia:MA15+
- Brazil:14
- Canada:14A (Manitoba/Nova Scotia/Ontario, DVD rating)
- Canada:18A (Ontario, season 4, DVD rating)
- Canada:PG (Ontario, seasons 6 and 7, DVD rating)
- Egypt:Not Rated
- France:10
- Germany:16
- India:15+ (self-applied)
- Ireland:18
- Ireland:15 (some episodes)
- Italy:Not Rated
- Japan:G
- Malaysia:18
- Mexico:18
- Netherlands:AL
- New Zealand:R13 (seasons 1, 3, 5 & 6 DVD rating)
- New Zealand:M (seasons 2 & 4 DVD rating)
- Philippines:PG-13
- Poland:16
- Russia:18+
- Singapore:NC-16 (season 2, DVD)
- Singapore:NC16 (season 2, HBO GO)
- Singapore:R21 (season 9, season 11, HBO GO)
- Singapore:M18 (seasons 1, 3, 4, 5, 6, 7, 8, 10, HBO GO)
- South Africa:16
- South Africa:13 (L, N, S, some episodes)
- South Korea:15
- Spain:18
- Sweden:15 (self-applied)
- Turkey:7+
- United Kingdom:18 (some episodes)
- United Kingdom:15 (some episodes)
- United Kingdom:12 (some episodes)
- United Kingdom:PG (some episodes)
- United States:TV-MA
- United States:TV-MA (DVD Rating - Seasons 1-3)
- United States:TV-14 (season 9)
- United Arab Emirates:PG-15 (self-applied)