buzzard said:
Back when I was DMing our home game regularly I generally tried to make it clear when a fight was too much for them. If they didn't take the blunt instrument hint that I offered, I fed them into the mulching machine.
I managed a TPK -2 (out of 8) in the final session before I handed off DMing duties. They had every indication that they were walking into an ambush, and yet they did it. I wasn't very sympathetic afterwards.
buzzard
My current group knows - but I had to teach some of them, over two very costly campaigns that failed and had to be restarted due to dead characters.
It was a hard learning curve, and I mayhaps would have done it differently, but the fact is players may not understand a DM's running style until they charge an obviously superior foe.
EXAMPLE 1: Party tracks a band of goblins and hobgob's to rescue some halflings in a cavern. One player notes the umber hulk lair, Umber Hulk bothering no one, and decides his 2nd level self is "going off alone to get all the XP's for himself." The party had to make 2 trips to get his remains.
EXAMPLE 2: party decides that they will raise the alarm in an evil temple themselves in order to "clean the place out at one time." In the end, they succeeded, BARELY, after fighting a running battle, and in the end, the wizard was the last one left conscious, having vanquished the last foe by PUNCHING him out.
EXAMPLE 3: A party enters what they KNEW was a trap, one at a time. It took losing 2 of the party before they stopped and regrouped.
After those examples, they learned that there are things in the world meaner than them, and they can only win against those mean things if they are crafty.
Last week, they were passing through a mountain range, hearing distant thunder. The "thunder" was a tribe of Hill giants obliterating a marauding orc band. After the orcs were dead, the party passed by quietly. The giants weren't looking for trouble.
Later, they actually TRADED with the giant band, gaining some pretty good stuff in the deal.
The important thing is the knowledge: Do your players know your style? will they take the information you provide that the danger ahead is beyond them?