[RPG] Does Heavy Armor reduce your speed

It’s very difficult to prove a negative, but I am reasonably confident that no rule in 3.5 or Pathfinder explicitly states that all armors of a given weight class slow you down by the same amount. In 3.5, at least, there were certainly a few super-heavy armors that reduced the speed by more than your typical heavy armor (Races of Stone had a couple of these).

So yes, every Medium or Heavy armor must somehow explicitly state its own speed reduction, even if the overwhelming majority of them have the same speed reduction. On the other hand, if a given case failed to do so, I’d just chalk that up to the designers not realizing there was no such general rule, since it usually is so consistent and armors which slow people more or less than others in their category are quite rare. It’s also worth keeping in mind that it is consistently weight category that we should consider, not sheer weight.

I found no mention of this issue in the books or sage advice, so you should make your own ruling.

We can see that both wearing heavy armor with low strength by the default rules and being encumbered by the optional rules reduces your speed by 10ft. If we treat these as equivalents, dwarves should never become encumbered because they wear armor. This leads to a pretty straightforward ruling: dwarves do not count the weight of armor they wear when calculating encumbrance.

This will also mean that they will reach heavily encumbered status "later" too, while under the original rules their carrying capacity is the same. So we add that the above ruling does not apply when checking whether they are heavily encumbered.