Damage rng reload pattern?

[Astro X]

Not sure this is really a thing, but I certainly have experienced it a few times. Here's what happened.

 

After dying, I reload the game and the same enemies seem to take and deal the same amount of damage as in the previous run. For instance, an archvile that took 5 rockets to kill, seems to always be killed with 5 rockets. Also, a baron that rolled 56 damage for example, seems to always roll that amount of damage should I take a hit from him. This was especially true when my girlfriend was fighting a cyberdemon in Triangulum MAP07. She'd tank 2 rockets at 200/200 no problem over and over in every attempt.

 

Has anyone else also experienced this?

[Edward850]

You are more than likely playing GZDoom, which not only stores the RNG index in saved games but also has multiple RNG tables between different action types including damage (this attribute is shared between Boom compatible ports as well when not demo recording). Doom's RNG is unpredictable to humans but is still mathematically deterministic when fed the same input (though not all ports share the same algorithm), which is a critical nature to how it's demos worked.

 

(Vanilla Doom did not save this index, ports that fix save game behaviour tend to add this however.)

Edited July 25, 2022 by Edward850

[idbeholdME]

I think the only way to change the result of a (G)Zdoom saved game is to quit the game completely and then reload so the tables get repopulated. At least that used to be the case a couple years ago, not sure if it changed over the years.

 

In vanilla, you will get different results pretty much always as a large number of things call and progress the same table.

 

RNG behavior is one of the few things GZDoom doesn't allow you to revert to vanilla.

Edited July 25, 2022 by idbeholdME

[Edward850]

3 hours ago, idbeholdME said:

I think the only way to change the result of a (G)Zdoom saved game is to quit the game completely and then reload so the tables get repopulated. At least that used to be the case a couple years ago, not sure if it changed over the years.

That's not true and never has been. GZDoom stores the seed of the twister it uses so it regenerates both the same state and position, regardless of if you've restated the game, loaded a different one or practically anything. The save serialization restores it exactly as it was.

[idbeholdME]

1 hour ago, Edward850 said:

That's not true and never has been. GZDoom stores the seed of the twister it uses so it regenerates both the same state and position, regardless of if you've restated the game, loaded a different one or practically anything. The save serialization restores it exactly as it was.

Good to know. Could be that when I tested it a long time ago, that the monster in question hit someone else before me, which changed the number.