The following rules make it much more difficult for PCs to permanently die, for two big reasons:
1) In fiction, main characters only die when it is meaningful to the larger story. In fact, surviving a near-death experience is a key part of the archetypal Hero’s Journey in myths.
2) In tabletop roleplaying, players have many hours of emotional investment in their characters. Understandably, a meaningless death can be very upsetting, and can cause some players to lose interest in the game entirely. Real-life friendships have been strained or lost over in-game deaths.
That said, meaningful death is still an option, and there are significant consequences for reaching 0 hit points.
If a player openly uses these rules to act invincible, just politely ask them to play within the spirit of the game.
In fiction, the main heroes rarely fall in combat. When the odds are turning against them, they often rely on a last bit of luck and willpower to cheat death at the last possible second.
To recreate this feeling in the game, Death Saves are replaced with Death Marks.
If they are Level 2 or higher:
All Death Marks are removed during a Long or Short Rest.
For dramatic purposes, a player may choose for their character to die instead of being revived. They can give their last words before passing on.
If their death is aligned with their background, or their sacrifice is meaningful to the overall story, their soul earns an eternal place in the Land of Legends.
If all of the PCs are Incapacitated or are about to be defeated — don’t let the story end!
Here are a few options to keep the game going: