While the new June update to 1.12.30 removed the extremely high sneak attack damage bonus (34x) with the hydrated status effect, the underlying numbers are still incorrect.

Details

Running some tests, the underlying problem seems to be that simply enabling the sustenance gameplay option doubles the base sneak attack damage that is in effect at that time. That is, if you have 2x sneak attack damage with no perks in stealth or concealment when sustenance is completely turned off in the options, turning it to "positive only" immediately doubles that bonus to 4x damage, without drinking anything. When drinking something on top of that, enabling the hydrated status effect, the calculation for that effect seems to be correct (+15%, leading to 4,3x damage), but still with the wrong base damage bonus (4x instead of 2x). Turning the sustenance option up to "positive & negative", being dehydrated leads to no sneak attack bonus damage at all (when it should be -15%). Drinking something again leads to the wrong 4,3x bonus. Now, when adding perks in the stealth skill, we still get the same incorrect doubling of the base sneak attack damage bonus when sustenance is enabled. So with rank 4 in stealth (2.5x sneak damage), we get 5x if we enable sustenance. However, if we add concealment perks on top of that, the entire sustenance sneak attack damage effect system seems to get disabled. With rank 4 in stealth + rank 1 in concealment, we normally get 3,1x sneak attack bonus when using ranged weapons. Enabling sustenance leads to the exact same number (not double!), and drinking something on top of that also doesn't bring any +15% bonus.

So, there seem to be two problems overall: -Enabling sustenance doubles the sneak attack damage bonus, when it should only add +15% when hydrated. -Concealment perks break the entire sustenance sneak damage system.

Game Version

1.12.30 (June update)

Language

English (EN)

New Game

Yes

Reproduction Steps

To start, have the sustenance gameplay option turned off. Then use a silenced ranged weapon to shoot another character while in stealth. Note the sneak attack damage bonus (should be 2x with no stealth or concealment perks, and higher according to any perks present).

Then enable the sustenance option by setting it to "positive only", but not drinking anything yet (no hydration effect). Do another sneak attack, the damage will be double the value it was before.