Eric Clingenpeel |
What Garretmander said, though you aren't limited to every other level like that. As long as both are even the next level can be either one while the level after that has to be the other.
I'm playing one in Dead Suns. Mystic/Solarian. When I was 4th level they were even. I had planned on taking 5th lvl as Solarian but we needed more healing so I took my 5th lvl in Mystic. You just have to keep them even.