Certification
- Australia:MA15+ (Season 1 - 4)
- Australia:M (some episodes, tv rating)
- Canada:14A (Manitoba, DVD rating)
- Canada:PG (Nova Scotia/Ontario, DVD rating)
- Germany:16
- New Zealand:R13 (series 1 and 2)
- New Zealand:R16 (series 3 and 4)
- Poland:16 (DVD rating)
- Spain:Not Rated
- United Kingdom:18
- United Kingdom:15 (season 3)
- United Kingdom:15 (season 4)
- United States:TV-MA
- United Arab Emirates:16+ (self-applied)