Does anyone have an idea what the difference between Random and Full Random is? I once thought that if I only played random (not full random) I could enjoy both random civs and variety and not have to play the same civ several times within a short timespan. But experience and some testing indicates that’s not the case.
Is it only the one previous pre-picked civ which is taken into account?
The game description for Random says:
Click to play as a random civilization which hasn’t been selected yet.
And Full Random says this:
Click to play as any random civilization. Previous civilization choices are not taken into account.
So from my understanding, Full Random ignores civ picks?
“which hasn’t been selected yet” 
The full random specifies choices (plural) but the random is a complete mystery to me. Not selected yet? Not yet since two games ago? Not yet since yesterday?
Not selected by another player in the game.
If player 1 gets the Franks (picked them or at random), player 2 cannot get them with random but still can with full random.
So full random allows a chance for mirror matches
Oh so it means not yet as in by another player in the current match as opposed to not yet in terms of previous matches?
Only the current match is considered.
In team games regular random notably guarantees not having redundancy for team bonuses as bonuses from the same civ don’t stack.
I had never thought of that. They surely phrased the description as vague and mysterious as possible.
But hold up, full random description says “previous” choices. Does it really refer to other players’ picks of the same match (which surely happen around same time if not simultaneously)?
Yes, if P1 got the Franks then the Franks won’t be rolled for P2. P2 got the Saracens so P3 will get neither the Franks nor the Saracens. They got the Chinese, P4 gets none of the 3. (It won’t change the probability for any player, the order doesn’t matter)
It’s never actually simultaneous but a simple RNG is fast enough not to notice (the whole process maybe takes a microsecond, keep in mind how powerful CPUs are compared to a human). First they grey out players who picked a specific civ then they run the RNG in order of remaining players, it’s quite trivial to code.
They really assumed the user to think in terms of line execution of the program’s code when they wrote this description?
No it’s just “random without mirror”. You somehow won’t get the same civ as another player.
Very easy to trick you into thinking it’s simultaneous while it actually isn’t
So they did assume that? Your response is a bit contradictory when you started it with no
On the topic of hairsplitting definitions of what simultaneous is, if the devs were that strict about it then I doubt they would use the word random at all. There is no such thing as random in computers, it’s all pseudo-random.
Nor is rolling a dice, it’s not truly random as you could precisely calculate on what side if would land if you know all the throw parameters. (And some tried developping that to cheat at casinos)
Likewise the clock goes so fast it’s impossible for humans to control it, hence in practice it’s random despite not actually being it.
Anyway : regular random = no mirror, full random = mirror is possible.