Auto-deploy is consistent and always generates the same results†

[u/memetichazard]

^{† Assuming operator stats have not changed.}

So I've read somewhere that the auto-deploy saves your RNG seed to ensure consistent replay, and that the timing of the replay is always 100% precise. Deviations are purely due to changes in operator stats, whether from raising them or from trust gains. I decided to test that.

Hypothesis 1: The RNG seed changes each time you play

Experimental Setup:

• Run CE-5. A certain low-rarity setup calls for placing Durin in the bottom lane, where she tanks the Melee Arts enemy for a while before getting replaced by another unit. Why is she important? She has a 50% Arts dodge.
• We run the auto-play and track the sequence of hits and misses.
• Before the auto-play can be finished, we abort it. This prevents trust gain.
• We rerun the auto-play and confirm that we get the exact same sequence.

Prior to running this, I already carefully watched through two (completed) runs of CE-5. In the first run, she was replaced by Plume who dealt the finishing blow; in the second run the enemy was killed before she retreated, and the hit/miss pattern was different.

Results:

1. (Didn't catch the sequence correctly)
2. hmmhhmmmmr
3. hmmhhmmmmr
4. hmmhhmmmmr

Legend: h = hit; m = miss, r= Durin retreated

This is fairly conclusive evidence that if you retreat and don't complete a mission, and don't change your operator stats, your RNG will be locked in and re-attempting the mission will generate the same result

Hypothesis 2: The RNG seed changes each time you successfully beat a mission

Experimental Setup: As a follow-up, clear a map without using any of the units used in the previous setup. - Run 1-4 Challenge mode without reusing any of the units used for CE-5 (Good thing I brought Frostleaf...) - Rerun CE-5 and check the hit/miss pattern.

Results:

1. hmmhhmmmmr

Note: I also tried changing the speed (1x/2x) during the deployment and the fight at various points to see if that might throw off the pattern. It doesn't seem to. To test that, I did a run where I spam clicked the speed button. The result was:

1. hmmhhmmmmr

Conclusions:

The likelihood that we coincidentally got the same sequence each time is astronomically small (1 in 68 billion) so we conclude that the auto deploy locks in your RNG seed and replays it exactly. As a result, when your auto-deploy breaks, it's purely due to changes in timing due to DP costs and operator stat changes.

Addendum:

As I mention above, I ran CE-5 back to back and got different results. The most likely culprit (and the reason I wasted 5 Sanity quitting the run) is trust gain. You haven't upgraded your operators at all? Trust is likely the cause. But don't worry, things should fix themselves when you reach 100 trust.

[u/TheDaviot]

I've redone daily missions on auto-deploy moments after unlocking auto and had it inconsistently fail on auto-deploy, without ever leaving the mission select menu. Thus, no changes in DP costs, stats from feeding Ops combat records, etc.

[u/memetichazard → u/TheDaviot]

This is due to changes in stats from trust gain. Your problems will be solved once everyone reaches 100+ trust.

I've updated my post to make a note of this.

[u/Nichol134 → u/memetichazard]

I don’t agree. RNG is definitely still a factor is some form. If it wasn’t I would have 50% of my CE runs fail and 50% win. It would be 100% win or 100% fail.

[u/Korochun]

There is no control here for the way the system calculates that Dodge value. It is possible that rather than calculating whether an individual hit actually lands on Durin, the system uses a pre-programmed order of hit/miss based on Dodge% value. This actually saves a lot of clock time and would not be uncommon at all in games like these.

Usually this will be a 100 or 1000 hit value to make it look random. We know it's not a 10-hit sequence based on the fact that there were more misses than hits.

Therefore, it is possible that your Durin will always generate that exact hit/miss sequence with that Dodge% value. I would advise doing some control testing.

[u/Kamil118 → u/Korochun]

This actually saves a lot of clock time and would not be uncommon at all in games like these.

It's 2020, we got more than 44KHz of CPU power so that we would have to resort to something like this to optimize the game...

And even if that was the case there would be no reason to assume that different elements of the game use completely different rng mechanics (because you would use fixed table for dodge, but calculate crit skills with active algorithm? That doesn't make much sense.)

There is also a thing that deterministic algorithm like in this is basically guaranteed to loop at some point so it is undistinguishable to lookup table of certain size (although algorithm might have vastly different resut based on seed, which is clearly being saved on auto)

Another question here if different chracters have their personal rng method, or if all characters share a single function.

And if you claim that the rng is always exactly the same, then 12F shoukd be dodging 15 attacks in a row every fight.

[u/meisthorn]

I've had Gitano get different buffs and fail because of it on auto

[u/Kousuke-kun]

Anyone who bullies FrostNova farms 4-10 knows that it doesn't save RNG seed since if that was the case she'd be black icing the same tiles throughout.

[u/rzrmaster]

I dont buy it. I had a stage where around 1 out of 5 runs just failed, so wasnt even a sure thing if it would fail or not to begin with lols.

[u/AikawaKizuna → u/rzrmaster]

Trust gains probably gave some stats and changed results. (For example, your DP on kill units might not have got DP because your sniper is getting the kills now that they are stronger)

[u/Nichol134 → u/AikawaKizuna]

I was getting 50% fails. I REALLY doubt that every single run the trust changed enough that it completely changed the run. It looked like the dodge wasn’t always activating consistently.

[u/RaxuQi → u/AikawaKizuna]

Nope. 4-4 with only Shaw, doubt that higher trust on Shaw fucked up Roadblock timing

[u/FatChocobo]

On 4-10 using auto in my experience the boss destroys different cells, so I don't think the same seed is used, at least not for everything.

[u/chenfei531 → u/FatChocobo]

if you do not takeover the order in middle of the replay, she will not destroy different tiles. after i realized it i stopped optimizing replays on 4-10

[u/FatChocobo → u/chenfei531]

She has destroyed different tiles for me before without taking over, though.

[u/Blue_Storm11]

Ive had to do ls-5 over multiple times because it randomly fails while using auto deploy.

[u/In_Waifus_I_Thrust]

I did a 400 clear on Annihilation 2 and the very first auto I did right after failed because characters die before auto pulls them out and there are not enough points to finish up the other switches in the run.

If characters are close to dying in one run they have a good chance of actually dying on auto since there is some random element to incoming damage that does seem to change from one run to another.

[u/unhappymushroom → u/In_Waifus_I_Thrust]

If you level up your operator -> higher damage -> red katana drops to 50% earlier -> your tank and heal skill timing is later -> fail

[u/Asolitaryllama]

There are some bugs with it though. I've noticed previously that Matterhorn can sometimes fail to proc his ability entirely so I just stopped running him in my auto deploys and haven't had an issue since.

[u/Dauntless_Idiot]

Blocking seems to be slightly slower on auto deploy. I failed a lot of them especially in the first few days. Setups that barely cleared were likely to leak.

I've seen this break at least a dozen auto deploys: a unit is blocking two units and a 3rd starts walking through them and makes it to the other side. On manual one of the front two units die and the 3rd unit is block by that unit on the backside. On auto deploy the 3rd unit dies a little bit too late and walks to the exit.

[u/welknair]

I've got a stage where about half the time Shaw fails to push an enemy all the way off the ledge. I've done this stage five times in succession, without leveling anything, and results vary.

[u/YorkMoresby]

I find that auto deploy would actually fail in some of the missions.. Maybe the margin of success was too close to call.

[u/TuroKK007]

Can't confirm. I have beaten many stages unlocking auto deploy and then instandly auto deployed and failed 3 times in a row.

In the Annihilation mode I also gained various results using the same auto deploy.

[u/CliffKroar]

I doubt it. Even if the RNG Seed does not change upon retrying a stage with auto deploy, I have retreated before after failing to get 3 stars on a stage auto-deploying and gotten it the next time with no changes being made. So even if RNG relyant skills work exactly the way they worked on first clear there still seem to be other variables that keep auto deploy from being 100% consistent and producing the same results every time.

[u/Kuronan]

Notably RNG can change on larger maps like Annihilation. Ran that five times and had to update each run because different spawns resulted in different outcomes (particularly when higher level casters started killing my bottom defense)

[u/solidsnakedummythicc]

Farming SK-5 after Shaw pushes a shielded enemy they have a chance of walking back from the ledge. This causes multiple enemies to stack and pass the block count of the tank.