How exactly do different difficulty levels affect the gameplay in campaign?

Question

Just wondering, how exactly different difficulty levels affects to the gameplay?

Does it switches AI into more aggressive mode, gives more starting money to a computer, etc.?

Answer 1

So, your interface is always the same. Marines always cost 50 minerals, and they behave the same way.

In harder difficulties, the AI is more agressive (attacks sooner and more frequently) and is smarter (i.e. better control over units), the enemies have more HP / attack, there are more enemies to encounter (Example, in the second mission, there's a little alcove north of the starting base with minerals and vespene pallets, on easier difficulties, there isn't any force there, on harder difficulties, there's a lot more), and harder enemies to encounter (on the third mission, on casual, my wife encountered zero mutalisks)

I don't think they give more starting money to computers, but I don't think they need to. On easier difficulties, the computer doesn't even use a fraction of the money it gathers.

Answer 2

For normal missions, the AI plays more aggressively, both in its attacking waves, and the strength of said waves. Expect more, sooner.

I'm not sure about the hero / covert missions, where you only have a single hero, etc., but any change in difficulty only is reflected in the AI -- you're never going to have to pay more minerals per unit by playing on hard.

Answer 3

I also have been searching abit on this but without any tangible answers. Here is what I found by both playing and searching.

As the difficulty increases:

• The game speed increases.
• Your opponent gets more units
• Your opponent starts with more upgrades, and researches earlier.
• Your objectives increases in volume.
• Your opponent gets more aggressive.
• Your opponent micros better.
• Map helpers disappear

I haven't seen any evidence to units getting more health beyond the obtainable upgrades.