Factorio Forums

I'm trying to deal 1 point of damage to an entity with 100 million health. The hit seems to register, but the entity's actual health doesn't appear to decrease.
As shown in the screenshot, "Damage to be taken: 1" is displayed. However, even after waiting for some time afterward, the entity's health still does not decrease.


D.O.R.A.X Setting :
shell Setting:

I then increased the damage to 10 and tested again. Strangely, only 8 damage was actually applied. It seems like 2 points of damage simply disappeared.

Why is this happening? Am I doing something wrong?

You are seeing effects caused by the 100 million health of the entity while the game is not focusing too much on health and stores health values as 4 byte float representing a health ratio (1 = full health, 0 = empty health). In order to deal 1 point of damage, the health ratio would have to go down from 1 (corresponding to 100 000 000 health) to 0.99999999, but latter is not representable as float and rounds up to 1. Next smaller float value below 1 is 0.999999940 which in case of your entity will correspond to health of 99 999 994.

Given that base game does not care about having entities with such insane amounts of health working nicely with miniscule amounts of damage, i would classify this as a Wont fix. In order to make your use case work, every entity with health would have to increase in RAM size, and budget for this is tight since it would include all entities like trees which is a lot in most saves. This would require having health ratio to be stored not as a float, but as a double.

Got it. In that case, I'll lower the entity's maximum health for now and then see if checking its health more frequently causes any performance issues. Thanks for your help!