Nicholas needs to get started in acquiring the systems adjacent to Mecatol Rex. He activates the Lazar/Sakulag system.
He then moves one of the Dreadnoughts out of Mecatol Rex into the activated system.
Steve has a PDS sitting on Mecatol Rex, which is an adjacent system. Since he has the Deep Space Cannon technology, which allows him to fire at fleets in an adjacent system using his PDS, he can fire at the Dreadnought that just arrived in the Lazar/Sakulag system.
According to the table on the Race Sheet, the PDS "hits" on 6 or higher. Steve rolls 1 Die for the PDS...
Steve rolls a 10 and scores a hit against the Dreadnought.
A Dreadnought takes 2 hits to destroy it. It becomes damaged, not destroyed. When playing Twilight Imperium 3 you indicated damaged ships (Dreadnoughts and War Suns) by flipping them over. When using VASSAL, as for this tutorial's graphics, a "damaged" flag is attached to the unit.