Death and Dying
Players dying must make death saving throws on their turn. 10 or higher doesn’t have to check a death box, but does not stabilize either.
Only another player can stabilize you with a heal check of greater than 15, or with some kind of automatic healing.
Checked failed death saving throws persist through an encounter, so if you already failed one earlier in a fight and go down again, you can only fail two more before death.