Originally posted by Daglar (Source)
Shared pool means that we intend to combine all PA’s earned on all of your characters, up to the maximum PA value available.
If you have 50 on character A, 100 on character B, and 250 on character C that is a total of 400 PA to spend per character.
The exp required to gain a level – the bar itself – is intended to be shared across all of your level 50+ characters. The intent is that if you are playing character A and log off at 50% of a level costing 500,000, and you log onto character B, you see the exp bar at 50% through the same level costing 500,000.