Any sex is implied

One scene shows a woman's bottom in underwear.

There are many people seen being shot. Some main characters are killed and we watch them die. People are seen with radiation poisoning . There are battles for territory.

Damn, Shit, hell ,Asshole are all used very infrequently. The version I saw on Netflix in 2014 had no S* words.

People are both seen drinking and smoking.

As the whole premise for the tv show is the fact that a nuclear bomb goes off there are many intense scenes that are very frightening throught all 2 seasons.