A common complaint about geological teams is that they can spend years on a small body such as an asteroid without either finding anything or confirming that nothing exists. Therefore I am completely changing the mechanics for geology teams in v5.70.
The chance of completing a survey team check during one year will be simply based on a combination of planet size and team skill. The formula is (1000 / BodyRadius^(1/3)) * (TeamSkill / 100)
So a team with a skill of 100 surveying the Earth would have a 53.9% chance of completing the task each year
A team with a skill of 120 surveying the Moon would have a 99.8% chance of completeing the task each year
A team with a skill of 150 surveying an asteroid with a 50km radius would have a 407.2% chance of completing the task each year.
During each 5-day increment, the chance will be equal to: Yearly Chance * (Increment Length in Seconds / Seconds in a Year). So in a 5-day increment of 450,000 seconds, a 100% annual chance would be a 1.45% increment chance.
If the check is successful a new mineral generation check takes place for that body. This check is identical to the one performed when the system was originally generated, except the chance for each individual mineral to be generated is 25% of normal. If the check for any of the individual minerals is successful, the size of the new deposit is compared to the one originally generated. If the size of the new deposit is greater then the amount of the original one, the amount of the mineral is changed to the new amount. If the accessibility is also higher then that is increased to the new level. If the size of the new deposit is less than the existing one but the accessibility is higher then the accessibility is increased to the new value.
I considered changing accessibility to a the weighted average of the old and new. However, if I did use a weighted average to increase accessibility of larger existing deposits, I would also realistically have to decrease accessibility in the case of a larger new deposit with lower accessibility. Players would often prefer smaller high accessibility deposits so this would often be a penalty not a bonus. In the end I decided simply changing it to the higher value was easier. The player benefits in all cases and the 75% reduction in generation chance should prevent this being too overpowered.
For example, assume a planet currently has:
Duranium: 100,000 at 0.8
Neutronium 50,000 at 0.6
Tritanium: 25,000 at 0.7
The team makes a successful survey completion roll and a new mineral generation check is performed.
A deposit of 30,000 tons of Gallicite is generated. There is no existing Gallicite deposit so that new deposit is added to the planet.
A deposit of 160,000 tons of Duranium at 0.7 accessibility is generated. The existing deposit is changed to 160,000 and retains the existing 0.8 accessibility
A deposit of 20,000 tons of accessibility 0.9 Neitronium is generated, The existing deposit remains at 50,000 tons and the accessibility is increased to 0.9.
No new Tritanium deposit is found so that remains as it is.
Whatever happens as a result of the successful check, including no new minerals, the survey is completed. The chance of the survey team making multiple discoveries over a long period is now replaced with a chance of multiple discoveries during the single check.
EDIT: I've also changed the experience mechanic for geo survey teams. They now have a chance of XP at any point while they are working rather than after a task is complete. This because of the widely varying length of the task for different size bodies.
Steve