If a reserve pilot is short called, they have three hours from the time of the notification. Occasionally there is an operational need for the flight to go out on time, or not be delayed further by a reserve pilot taking their “full 3”, so at their discretion scheduling can offer Move Up Pay, which is 1.5 hours per each duty period in the trip. However in accepting the pay, the pilot must be able to make the earlier report time.

The advantage for a reserve pilot is that this 1.5 hours (as much as 6 on a four day) goes “on top” of reserve guarantee.

So one poster here is saying if a reserve pilot were to say “no” to a move up pay assignment, and the company was desperate for the flight to go out, they could potentially call a line pilot on their day off and offer them premium pay (200%)

I guess his rationale being that collectively we should fleece the company for maximum dollars by sacrificing your individual opportunity to fly it for less money.. or maybe that new guys should learn to play ball and let senior guys make money because one day it will be their turn.. personally I would never begrudge any new hire from flying a reserve assignment for extra money.

In reality scheduling would probably call another reserve pilot who would gladly take the trip anyways, you have no way to know what their next move is.