If you declared that you were using Incap for that attack, you have to use Incap. So say you target Character A with Incap and he succeeds on Shape Change, if there was a legal Character B to attack with Incap that you wanted to attack, you would have to use Incap since you already declared that's what you were going to do.

What if a Shape Change is made, but there is not another target?

1. Today it came up but both people that were playing didn't hear of this rule. A Shape Change was made on a close combat attack. There was not another character to target, so the attacking player tried to roll to break away. I mentioned that they couldn't and had to take an action token (as I understood it). They disagreed and read Shape Chance in the PAC and said it was legal. I believe it isn't. Am I crazy? What is the correct ruling?

2. AvX Thor tried to Running Shot my AvX Emma Frost. I believe my Shape Change roll is made after they move but before they attack. My opponent had me declare and roll my Shape Change before he moved. Once I hit my Shape Change, he moved away into the corner, because there was no other target. This was similar to scenario #1, but there was no break away roll needed. I believe this sequence was incorrect, but I wanted to make sure before I brought it up.

You were correct. If there was no other valid target when the attack was declared and Shape Change was successfully rolled, then the action resolves without an attack.

You were also correct here. Shape Change is rolled when the attack is declared, which happens after movement with Running Shot. If you hit your Shape Change roll, the attacker would have to either declare another valid target, or end their action.

Thanks a lot!

Clearly they did not read it from a current PAC:

SHAPE CHANGE When this character is chosen as the target of an attack, you
may roll a d6. On a result of [5] or [6], the attacker can’t target this character with an attack this turn and the attacker may choose another target character instead. The attacker then makes the attack unless there are no targets, in which case the action resolves without an attack.

No they read it from the current PAC... I play with a lot of players that have been playing for a long time and have been playing at home and staying away from the venues. I, however, do both and browse the Realms daily, so I'm fresh on the rules. So when I say hey, you're back in the Stone Age, they argue it or read and interpret rules differently. Most won't even take an answer on a thread legitimately unless it's ruled by an Orange, then they'd even go further and say, who are those Orange's anyways? Let's e-mail WizKids and wait 1 month for a response. It gets very frustrating playing certain players in my area. They're extremely good, but sometimes look into things too much when the answer is very simple. Sometimes, I find myself on here posting basic questions looking like a new guy to challenge their stubbornness.

The irony is of course that the Rules Deputies are the ones that answer the rules e-mail, so they get the same answer there as here...

I know lol. I explained that to them as well. Oh well...