Bethesda have finally split Fallout 76 into two modes - Adventure and Survival. The former will be the one players had all along with some minor changes while the latter is an addition for those who didn't like the PvP restrictions.
Fallout 76 has been overly punishing towards players who wanted to do some PvP initially, prompting Bethesda to announce the new Survival mode back in January 2019. The latest patch finally brought it to life and players can now choose whether they want to go play with friendly or competitive Vault Dwellers.
Those who wish to play by the old ruleset can do so by choosing the Adventure mode. It will remain the same for the most part but the "slap" damage will be completely removed. "Slap" damage was the reduced damage adventurers would take from other players before shooting back and entering the PvP mode.
Furthermore, damage numbers will receive additional modifiers in PvP regardless of whether it's in Survival or Adventure mode, in order to prevent players from one-shotting others. It is not guaranteed to prevent all one-shots but the chance will be "greatly reduced".
Speaking of Survival, the mode will make players hostile towards each other immediately but they can put their weapons away to enter the neutral mode and show they mean no harm to each other. Or they could just pull a gun later on and kill them anyway, so this should add some tension.
The initial damage reduction does not exist here and players take full damage from other players at any given time. To avoid infinite healing, players will not be able to apply the effects of the same Stimpak version more than once.
One interesting bonus in Survival mode will be that all players will earn 20 per cent more experience, which is likely there to offset the potential risk of running into bloodthirsty Vault Dwellers who won't hesitate to give you a Gauss Rifle facial makeover.
You can read the chunky patch notes on Bethesda's official website.