[0.15.3] Research bonus descrepancies / confusion

[malventano]

- Lab research speed bonuses currently ramp up in 10% increments per level, starting with 20% at level 1, but those do not appear to stack (30s items take 21 seconds at level 2, which means it is -30% and not -20% stacked with -30%).
- Mining productivity research states the same 2% amount for each level. Presumably, these do stack.

The difference between these two is confusing, especially since they are two adjacent science items with a completely different (fixed/stacked) bonus amount. These need to be more clear. If lab research speed is meant to be a total bonus, the description needs updating to state that.

I believe the mining productivity bonus should actually be changed to match that of the lab research, and also state that it is a total bonus amount.

It would also help the situation for both if mousing over labs and mining drills/pumpjacks showed the current research related bonus being applied to those items. Currently, the only way to know is to sit there timing a cycle with a stopwatch.

[Ranakastrasz]

I would note that +20% speed and +30% speed add up to +50% speed, or -33% duration. This means I would expect a value of 20 seconds, off by 1 second, instead of the 15 seconds I think you were expecting.

Admittedly, math with percentages gets really messy if you aren't really careful to explain exact mechanics of how each value adds or multiplies. 50% more than 50% more might be 100%, (Additive), 125% (multipltive via 150% * 150%, or 1.5*1.5) or 75% (50% + (50%-(50% of 50%))).

It gets more fun with subtraction, since you have to make sure you don't go negative. Factorio modules cut power costs linerally with efficiency modules, but are capped at -80% normal, instead of just applying a 80% multiplier per module.

In any case, there are a few possibilities, and 20 is close enough to 21 that you might have miscounted. Or not.

[malventano]

I totally could have miscounted, but either way, I believe this could be made clearer. If these are indeed stacking, perhaps the wording should be tweaked to state that the bonus is adding an *additional* percentage?

Also agree with your point on if the percentages are purely added together prior to performing the multiplication, or if they are recursively calculated/stacked. The game should somehow present that to the user. I still believe the solution there is to add the current percent gain to the mouseover info of a lab.

*edit*: Ok, did some timed testing in game. The bonuses are additive, summed together for a total speed increase to the lab.