Disengagement Chance Explanation? (2024)

I’m not seeing real good explanations for the Disengagement mechanic for warships, either in threads here or on the Stellaris Wiki. Mostly I’m trying to understand how disengagement works differently for different sizes of ships.

The way I’m reading it is that a ship that gets hit with a shot while already below 50% of hull points, compares the new shot’s damage against normal hull points as a percentage and then applies the Ship Disengagement Modifier to the damage percentage. So for example, a Corvette with 300 hull points normally has already taken 150 points of hull damage. The next shot coming in does 60 points of damage, which would be equal to 20% of the normal hull points. The Corvette doesn’t get a modifier to its disengagement chance (assuming no tech or leadership bonuses), so the Corvette rolls disengagement with a 20% chance of success. If a second shot comes in at the same level, the Corvette gets another 20% chance, while a third shot would simply finish off the Corvette. At these rates a given Corvette would disengage 36% of the time before it’s destroyed.

Alongside that Corvette is a Battleship, also getting hit for 60 points per shot, which would be equal to only 2% of the normal hull points, but it can get hit like that 24 times before being destroyed on the 25th. It would have a 2.5% chance to disengage per shot, as it gets (at least) a 1.25x multiplier per chance, and with 24 chances to disengage, it would do so an average of about 45.5% of the time. Doubling the damage per shot to 120 and giving the ship half as many chances actually improves the Battleship’s odds a bit, taking total chance to evade to 46%; doubling again makes it 46.9%.

Is that in-line with the understanding of how disengagement works? Does someone know where a better explanation is and can they point me to it?

That is more or less an accurate description of how the system works, with a few caveats:

Firstly, the base disengage chance is 75%. This means that a ship at half health that takes a hit for 25% of its max hull points has a 37.5% chance of disengaging.

Second, there is a define labeled “max disengage chance”, which is set to 50%. I am reasonably sure that this means even if a ship at half hull takes a hit for 49.9% of its max hull, its still going to only have a 50% chance of disengaging off of that hit.
This is really important, because it means that while fewer larger hits generally slightly raises the chance of a ship disengaging, there is a break point where even higher damage hits greatly reduce the overall chance a ship has to disengage, even if it doesn’t kill the ship outright.

The combination of this max disengage chance and the fact that finishing blows don’t allow a ship to disengage off of them means that a lower health pool leads to on average fewer disengages, and thus corvettes have an even higher mortality rate than their low disengage modifer would indicate.
Battleships are generally the best at disengaging, because they can actually take a neutron launcher shot at half hull and not die, and with the hull bonus techs and a bit of luck, they might not even go over that 50% max chance threshold from one hit, so they dont waste nearly as much disengage chance as other ship types.
Crusiers may have a higher modifier than battleships at 1.5, but they are very likely to just die outright from x weapons or neutron launchers once at half health, and even if they survive they are definetly running over that 50% threshold, so they will suffer more losses against those heavy weapons.

Also there is a 1.25x multiplier on disengage chance for being in friendly territory, which for some reason doesn’t get mentioned anywhere in game or on the wiki as far as I can tell.

Cordane said:

I’m not seeing real good explanations for the Disengagement mechanic for warships, either in threads here or on the Stellaris Wiki. Mostly I’m trying to understand how disengagement works differently for different sizes of ships.

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The disengagement system is poorly documented, and to my knowledge no one has bothered to perform controlled experiments to study it, and if anyone has done that I've never come across a post explaining the results.
With no official explanation and only limited unofficial explanations, you're left with the current situation. This thread is the most comprehensive explanation of the disengage system that I know of.

Cordane said:

Probably coincidental that this flat amount of damage produced results like that, but I think I see where you're going with the explanation. Thanks!

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This looked very strange to me, so I threw together a quick spreadsheet. I've been going by the explanation provided above by @Razor Feather

Columns A, B, C and D are respectively

• Damage dealt per hit (the variable everything is expressed as a function of)
• Number of hits the target can receive (fatal hit is accounted for)
• Chance for the target to disengage if hit a single time
• Chance for the target to disengage if it receives the maximum amount of possible hits (1-(1-C)^B)

My conclusion is that the total chance of a ship to disengage is (mostly) independent on how many hits it takes, meaning it is independent of both target's health and attacker's damage per hit. The only exceptions to this is when you're down in the range of very few hits, and can strike a killing blow in one or two hits - at that point disengage chance is limited by the 50% chance cap or because the target dies in first hit.
Further concluding on this, it seems that dealing less damage per hit is only a problem if it brings you out of this critical area, meaning weapons like disruptors and autocannons are not nearly as bad as some would claim, as other S weapons are already "non-critical". Inversely, it means that X weapons, neutron launchers and to some extent also kinetic artillery are all significantly better than one would expect, as they are "critical" unlike their alternatives.

Gobbibomb said:

Ok, But if ship have 30% hull but 100% shield and armor when get hit to shield go to disengage?

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This thread is 4 years old.

Abdulijubjub said:

This thread is 4 years old.

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It's also very very out of date

currylambchop said:

It's also very very out of date

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ok, but thread wasn't close :S

Gobbibomb said:

ok, but thread wasn't close :S

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Threads don't automatically close. Instead, there's an automatic warning before you post on any thread with more than 6 months since the last update.