I was wondering if anyone could help me. I'm going to be DMing a party of six or so PCs. I'm glad to enough PCs, but I'm having trouble designing adventures. When they all get to second level they will have a combined level of 12 and an average level of 2. Now a monster with even a CR of 10 would eat them alive, while a monster with a CR of 2 would just lay down and die. I know I can put them up against a bunch of low level monster, but that can get old. So, where is the happy medium? What single CR level can I pit them against and give them a challenge without ending in massive amounts of PC death?