I've been redirected to this thread and it's probably a good place to post my ... experiences with prospecting.
First, though, let's see if I got all this correctly.
Considering a given planet square. Let's say it's a Cave.
1. At some point prior to prospecting
(probably during creation, but it hardly matters) it is determined whether this square has a deposit. This is done using the "Terrain Probability" given in the rules. Since it's 10% for caves, about 10% of all caves do have a deposit in this game.
1b. The type of deposit is determined by the method explained under Economy - Mining - 7/ Determining Type of Deposit
1c. Taking Ellias' statement
“The chance of a deposit is fixed, its not decided each time you prospect. ”
and Tey's neat height bar example, I figure that there is also a fixed predetermined chance of finding this deposit. (Where "chance" is the wrong word really, it's more like a "(prospecting) threshold".)
As this is in no way indicated in the rules, how is this threshold determined?
[Side note: Interesting implication of the above.
* Fixed amount of squares in the game, with fixed predetermined deposits
=> fixed amount of deposits in the game.
* A deposit will run out eventually and might be replaced by a new one or NOT
=> amount of deposits in the game will diminish over time.
* Unless new deposits are "spawned" by admins, the Combine will eventually run out of mats at some point.
2. Now, getting to Prospecting
According to the rules section the chance of finding a deposit is
Chance of finding = ( 1 + Total Sensors(Comp Op/30+0.05) ) * Terrain Prob
If I got it all correct, when you prospect this value is compared to the predetermined "prospecting threshold" and if it's higher, you have found the deposit. If it's lower you didn't and no subsequent attempt can turn it up, unless you increase skill or sensors, thereby increasing the "chance of finding". (Again it seems that "chance" should be renamed to something like "(prospecting) strength", since it's not a chance/probability.)
Now, is this correct? If so, the rules should be reworded since they give the entirely wrong impression how prospecting works. This would be due to the order and structure (for instance, "7/ determining type of deposit" right between "6/ finding a deposit" and "8/ building a mine", clearly indicating a direct linear connection to the reader that's just not there.), as well as the wording and omitting of certain facts (like the existence of a "(prospecting) threshold").
Additionally, and finally, I have two observations of my own to state which would be perfectly in line with the rules as written in the mining section, but not with the rules as stated in this thread. So, there probably is either a bug or a misunderstanding.
1. Here is an excerpt of my personal general events.
“ 164 Year 11 Day 157, 9:31 You gained 150 XP with the following message : You have discovered a deposit of quantum.
165 Year 11 Day 157, 9:31 You have found quantum on planet xxx at (3, 0) of size 59,670 Units.
166 Year 11 Day 156, 23:14 You have started prospecting on planet xxx at (3, 0).
167 Year 11 Day 156, 22:31 You gained 50 XP with the following message : You Completed Prospect Survey Of Area. Nothing Found
168 Year 11 Day 156, 22:31 You have completed scans on planet xxx at (3, 0). You found No Deposits.
169 Year 11 Day 156, 12:21 You have started prospecting on planet xxx at (3, 0). ”
You will notice that I found no deposit on a prospecting run, but did find a deposit running the exact same scan again. Yes, I didn't level, don't have more skill points and still just a single FK-7. All was exactly as the first time, I didn't even move. I didn't realize it at the time, but according to previous statements in this thread, this must be a bug. (Confirmation?)
However, according to how the rules are actually written and taking the "chance of finding a deposit" as a real chance, it could indeed happen to not hit a 23.8% chance on a scan, but do hit it on a subsequent attempt.
2. I found 17 deposits on 19 squares on my planet, with a single (1!) FK-7 and a CompOps skills of 2.
If the above statements of having predetermined deposits on all squares is true, and the "Terrain probability" averages roughly 10% on my planet. The chance of having 17 deposits on 19 squares at a 10% chance is really low. [edit: removed faulty calculation, will update tomorrow].
Additionally, all deposits would have to have a "prospecting threshold" of below 23.8 (CompOp: 2, Sensors: 10), making it even less probable.
I'm aware of the Law of Large Numbers and the fact that just because it's improbable doesn't mean it's bugged, but this is a really low chance and seeing that there might already be a bug it might be worth looking into.
Phew, lots of stuff. Last, but not least, I'm not complaining or trying to hit on the people writing the rules. If anything sounds like that, I apologize.
I'm just trying to figure out how stuff works and to help to improve the game in what little way I can (and if it's just the rules section :D ).
edit: removed faulty probability calculation