Curious about difficulty levels and effects?

[Linamints]

I was discussing the variables in Alpha Centauri with a friend earlier when he asked me what the difference was between the difficulty settings, and I realized I actually don't know.
I know the AI's are more advanced/hostile at higher levels, but what else does the difficulty level impact?
I've found it difficult to find detailed specifics on this. I've always played on Transcendent so I'm not sure what the others do.

[JarlWolf]

Well its a general rule of thumb that the amount of drones increase with each difficulty level, and the native life also becomes more aggressive I believe. Someone like Yitzi or Ete would probably know better then me, I typically stick to Thinker.

[Buster's Uncle]

Your odds of winning any given fight go down with each level, too, and diplomacy with the other factions is more hostile.

[Geo]

And the easiest 3 levels have a 100 turns more to achieve a victory.

[Dio]

Also, at transcend, I do believe that the energy output of your bases is only 2/3 of what you would get at lower difficulty levels.

[Buster's Uncle]

Also, at low levels, you can switch production in your bases without mineral penalty, and change SEs without paying - the price rises at higher levels.

[Sigma]

Below Talent, you don't need to pay extra for Prototypes, and at Talent and below your AI opponents cannot build secret projects that you don't have access to. So if you don't have Planetary Networks but Zakharov does, he still can't build the Virtual World until you discover it.

[gwillybj]

Prima Guide, pages 18-19:

AI Computer-Player Effects:
1. Easier Diplomacy. Except Intense Rivalry.
2. Delayed Gang Tackles.
3. No Mind Control. Citizen, Specialist, Talent.

Misc. Diff. Effects & Handicaps:
4. Secret Projects. As above: At Talent & below, others will not start if you don't have the Tech.
5. Colony Pod. Citizen, Specialist: won't abandon size 1 base.
6. No Early Research. Citizen & Specialst: no research points during first 5 years.
7. Command Center Maintenance. Citizen always 0. Specialist & Talent always 1. Librarian & Thinker starts at 1, rises to 2 at Fusion Power. Transcend starts at 1, 2 at Fusion, 3 at Quantum.
8. No Power Overloads. Citizen & Specialist.
9. No Population Lost to Attack. Citizen.
10. Random Events. Do not occur before [75 - (DIFF x 10)]).
11. No Prototype Cost. Citizen & Specialist.
12. No Production Penalty when switching production. Citizen & Specialist.
13. Cost to Change Society. CHANGE^3 x DIFF, where CHANGE = number of areas changed. (1=DIFF, 2=8*DIFF, 3=27*DIFF, 4=64*DIFF). NOTE to mathemeticians: Is this right? Some of the formulas in the Prima Guide seem off.

[Kirov]

As gwillybj says, the effects are numerous, but I find that 4 of them are most important:

1) At Transcend, the second citizen is a drone already.

2) AI gets an Industry penalty at lower levels and a bonus higher up. I think it pays like 130% at Citizen and 70% or 80% at Transcend.

3) SE costs rise up to 40 EC at Transcend.

4) There is something about facility maintenance which I don't remember at the moment. I'm quite sure at Transcend the AI pays only 1/3 energy. And maybe you get a discount at lower levels.