Invader Arrival Chance
The annual chance of an invasion by the Invaders is changed to a new formula. For v2.5.1 the chance is:
5% * (Years Since Invaders Activated / 20) * (Increment Length / Year)
The new version is:
(Largest Rift Diameter in million km ^ (1/3))) + 2%) * (Increment Length / Year)
For example the annual chance after 30 years of invaders (assuming usual 10% per year growth).
Old: 5% * (30/20) = 7.5%
New: (175m km ^ (1/3))) + 2% = 7.6%
The annual chance after 50 years of invaders (assuming usual 10% per year growth).
Old: 5% * (50/20) = 12.5%
New: (1174 km ^ (1/3))) + 2% = 12.5%
The reason for changing the calculation, even though the results appear to be similar, is that I am going to add some options for increased invader threat by increasing the size of rifts. The new formula will increase the invasion chance based on the increased rift size.
Enhanced Invaders
v2.6 adds an additional option for Invaders. This is a separate checkbox called ‘Enhanced Invaders’ and will only function when the normal ‘Invaders’ option is active.
If Enhanced Invaders is active, there is a chance that a new Aether Rift will be larger than 10m km.
The 10m rift will appear 60% of the time. For 30% of rifts, extra 2-100m km will be added to the diameter (rolled as 2 x 50m) and for the remaining 10% an extra 2-1000m km will be added (rolled as 2 x 500m).
As the chance of invaders appearing and the size of the fleets is based on rift size, this can lead to much larger invasions earlier in the game.