It was D&D 3.5. The DM was experienced but it was his first time running 3rd and he didn't have a good feel for it. He wasn't explicitly trying to kill us, just challenge us, but he had a habit of overestimating what we could actually handle. But, there was basically an unspoken gentlemen's agreement that we would approach combats "heroically". In truth, many times we didn't have much of an option to do otherwise (we could have tried to run, but that would have meant dying tired, since monsters could typically outpace us). As a result, we averaged about 1-2 deaths per session (I think the campaign ran roughly 140 hours or so, total). By the end, I'm pretty sure no one in the party had even met a PC who had met a PC who'd known a member of the original party.