Characters in this story are threatened with tangible death over a period of time and are actively trying to survive the situation.
Examples could be characters stuck in a Death Game/Battle Royale, a Natural Disaster, a War, or are stranded in space with little oxygen, etc.

Do not use the tag for punctual threats, where no focus is made on survival as the goal, as this tag is not here to tag every VN featuring death fights, which are pretty common with settings such as fantasy, featuring weapons such as swords.