Ruin Explorer
Legend
5e is dangerous over the course of an adventuring day.
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If failure is not allowed to happen at a table then yes, 5e is not dangerous or tension filled.
These two points are well made. The issue with the first is that it takes a lot of encounters to kick in. 5E chose a high threshold at 5+ encounters, I feel. Outside of actual dungeons it is often hard to plausibly have 5+ resource-draining encounters in a day. Which means playing 5E in a more naturalistic or sandbox-to way can lead to lessened challenge and/or swingy encounters (if you try to compensate with increased difficulty). Particularly in overground situations. I think if they'd set it to 3-6 instead of 5-8 we'd see far fewer people experiencing issues here.
The second point is unarguably true though. Any edition can be run that way. I actually saw it a fair bit with 2E and 3E and less with 4E because it was far easier to have an "accidental" TPK in those editions, especially at low levels. Whereas 4E encounters tended to go as expected more, from the DM side. 5E just has the issue that it is easy to accidentally "go easy" on the PCs by not having enough encounters/day. I've still seen plenty of deaths in it though.