D&D 5E How hard is it to accidentally have a TPK?

[MarkB]

One thing that can contribute to a situation turning into a TPK is groups having really bad exit strategies. I recall a couple of times in my early 3.5e days when we all agreed that we absolutely, definitely had to get out of there - and then it turned into a conga-line of heroic sacrifices, as everybody tried to stay behind and cover everybody else's retreat.

 

[Draegn]

I find that most TPK happen at our table due to bad luck. Our game is extremely deadly if you engage in combat to begin with. With a homebrew critical hit rules and damage chart my players tend to be very careful.

Four of my players all arcane casters decided to stay up on the city wall during a seige with a problematic NPC. The section of wall they were on for lack of better word was the conjured elements of firey acidic frozen hell. The poor little half trolls and trolls were having a bad day until one of their priests cast her own spell. By chance the casters and NPC all failed their saves. So now Mister Problematic's enslaved demoness is free to remove by any means the ring that controlled her and the trolls are climbing over the walls.

What will happen to the helpless characters?......... I left them with this cliffhanger until next week.

 

[jasper]

Bad luck can kill the pcs. And they should die and not get a "get out jail" card. Friday night my luck turned bad. The group was running without healers. First big combat we win but I have to burn 6 out of my 7 hit dice during the first short rest to get close to full. After the second combat I burned my last hit dice and 3 potions of healing. Got me back to 32 hit pts. About half of my hit pts backt.
Final combat. First round Horn of blasting is tooted. Roll 14% it blows up. Lucky I only take 31 pts of damage. The rest of the groups runs away (they had taken damage from the monster). 2nd round the party leaves then the monster eats me.
So yes a TPK can happen due to bad luck and the dms should let it happen.