Each pair of people have a chance of being aligned with each other. However, alignment is not transitive. That is, if A is aligned with C and B is aligned with C, it is not necessarily true that A is aligned with B
Alignment can be checked at any common altar with the following ritual:
Required materials: 4 candles per ritual.
You will get a message saying whether you are aligned or not once the ritual is sucessfully completed.
In the Old Days a group of five pairwise aligned players was required to pass the Test of Astrological Alignment.