DESC: Your species is split into distinct groups that often have very different looks and/or powers. While this is similar to a sub-species the difference is in that they all live together and are controlled by a single ruler. Subspecies on the other hand will have a separate ruler. This power does not mean that all the split species get along, it just means that a single ruler governs them directly.
When making the split species you can have as many separations as you want. But each species designed must share the same base population divided by the number of splits you will have. They must all include this power. Each member of the species is awarded an additional 300 population after the split.
So with 2 splits the starting population is (6000/2) + 300 or 3300 per group for playable species (non-playable start at 5000). If you have 3 splits it would be 6000/3 + 300 or 2300 per group for a playable species. A non-playable species would be (5000/2) + 300 or 2800. This is the total starting population each split has to build with. Power, Ability and Class cost are not changed.
The XP Gain is typically figured at [starting population]/50. The Power Split increases the divisor value by the number of splits you have. So with 2 splits the value is [starting population] / (50 +(2 x 15)) and for three splits it is [starting population] / (50 + (3 x 15)), always round the divisor up.
If I spend no population and only have split with 2 species then I would divide 3300 / (50 +(2x15) ) or 3300 / 80 which is 41.25%. With a three way split the formula would be 2300/ (50 +(3 x 15)) or 2300 / 95 which is 24.21%
The total starting population is a combined total of each species in the split and you will need to keep a record of each species in the group seperate to determine population changes.