You balance it with a reset upon using a waypoint, travelling to a town, or entering an instance. Or you make it similar to the killnstreak timer in D3 but a bit longer so if you spend too much time out of combat it drops off.
Plus with scaling, there will be no low areas.
Well no low areas but weaker enemies after all. I donât think, it should he designed like a race. (Thatâs a main problem)
When you want to farm a specific boss, you HAVE to restart the game, port back etc.
I think, the reward should be for staying alive in general, not for slaughtering a lot of enemies in a short period of time.
F5
Save the progress.
Continue your gameplay as time permits, F5 along the way. If you die, reload previous save.
Easy solution here, really. EZPZ. But, weâre dealing with blizz/diablo devs, so good luck with imbuing reason therein.
an other reason, online only might be a better idea
there is no saving 
That is exactly what I have been arguing.
Just make it XP based, so harder areas will automically build your survival bonus faster.
Also, spending tens of hours increasing your survival bonus on easy content is already an opportunity cost.
You would likely have been better off just doing the harder content without that bonus then.
Which is also why, a survival bonus need to take a looong time to max. Not like the âsurvival bonusâ (yellow pools) of D3.
So it feels like something that comes slowly while playing naturally, and not something you go âgrindâ before getting back to the real game.
Youâve convinced me on this point. I will concede that providing small but meaningful bonuses for staying alive and losing these bonuses upon death looks to be a better approach for the game on the wider scale of encounters. Losing these bonuses upon death and having to build them up again to full efficiency seems reasonable.
yea, thats what i tought
Yeah but you need combat involved for that or else you could log in leave town find a safe spot and sit and build up said bonus.
In D3 inthink itâs like 5 seconds of not attacking or being hit and the streak falls, it would be longer than that, but bosses are in instances, so it would reset upon entering.
ur not gaining any xp, standing around in town
and ur getting xp faster when you kill mobs faster
there doesnt need to be any race theme to that
killing mobs fast, already rewards itself
Ahh, basing it off xp gains.
As much as I like what Sacred 2 did with its survival bonus, the one mistake they made was making it build on âtime in combatâ. So some smart people simply found a low lvl mob, went into combat and went afk 
XP gain is a much better way indeed.
aaaah i never knew much about this system (sacred fanboy)
yea that would be the best way
Well scaling would help with that since even level mobs would eventually kill you. But there is no xp gain in my version. Also the buff wouldnât infinitely increase or anything, thinking of something similar to 3 stacks of nephalim glory.
yea ofc. you have to cap this somewhere
but basing it on xp gain would still be the best way to do it
Imo, while there should certainly be a cap, it should be somewhat high to have any meaning. Hard to say how much, it depends on whether you can get MF from other sources, and general scaling of dmg etc. (how much faster do you kill stuff if you go all in dmg and dont care about survival, basically).
But Iâd say anywhere between 100%-500% MF bonus when capped. And something like 30+ hours to max in a normal end-game scenario (since it is xp based, it depends on your kill speed and difficulty of course), but on a curve, where maybe you get 1/3 of the cap after 5 hours, 2/3 of the cap after 15 hours and that last 3/3 part might only be after 30+ hours. So you get a decent chunk of the bonus relatively fast, and later it starts to go slowly. Not because making it grindy is the goal, but
Instead of XP gain, I guess another way could be by key dungeon completion (and other end game activities). Like you complete a Key dungeon lvl 1 and get 1 point, but if you complete a Key dungeon lvl 10 you get 10 points etc. And maybe it takes 10000 points to cap the bonus or whatever. That way you would enforce that you couldnât just go out into the normal overworld and kill easier mobs.
if key dungeons would just gave you a lot of EXP for clearing, it would be easier to implement and balance
Sure. But if XP is also used for other stuff in end-game (lvling, âparagonâ whatever) it might be a problem.
why? normally, the harder the task is, the more xp you get, to increase your level, paragon, what ever
so why not also get rewarded with a higher mf find bonus
It depends on the how everything is balanced of course, but in D3 everything is way too heavily skewed toward GRifts. Probably wouldnât be a bad thing if the xp in those werenât as high as it is - making other activities more rewarding. It would make a lot of sense that GRifts rewarded more survival bonus for its difficulty though. Since you lose it all on death, dangerous content should be much more rewarding - for lvling/paragon though, the most dangerous content should maybe not be endlessly more rewarding, as that would have the opposite effect of survival bonus, encouraging âgraveyard zergingâ.
But hopefully D4 doesnât have that kind of scaling and miss-balance between endgame activities, so it might not be an issue.
XP seems like the simplest, best idea. Just saying there could be cop-like alternatives for balance reasons.
yea it should probably also be scaled along character level
so with level 1, only getting like 5 xp for something, wont make you take a year to max the bonus, while in max level, it would only take you a minute.
this can be balance eighter, with scaling the xp gain in the first place
or with scaling the mf bonus to the character level