I just want to make sure I'm understanding the Rolling rules correctly, especially as factors start interacting with one another. I know if I were going to roll a d6 skill die, when hindered, I would instead roll a d4. If I received help from an ally, the'd roll their skill die and we'd take the higher result. I'm a little confused on two scenarios: 

1. What happens when your skill die is higher (especially when significantly so, like a d10 or d12)?
   1. My current understanding is that even if I have a d12 skill, if I were hindered, I would roll a d4 instead. Is that right? In other words, no matter my skill, unless I'm assisted by someone else or external circumstances, I can't roll a Success while hindered.
2. Is it possible/allowed to be hindered by injury but assisted by circumstance?
   1. What happens if I'm also aided by an ally? Would we roll three dice in total, me my skill die and a d6, and my ally their skill die, taking the highest of the three?

Thanks!

Being hindered lowers your own skill die to d4, no matter what how skilled you are  normally. This is to make the GM’s job easier and cut down on time spent trying to find the right dice or track numerical modifiers. Coming up with creative disaster and setback results is hard, and ultimately more important in this style of play than numerical modifiers, so “use a d4 if you’re in trouble” deliberately ignores the character’s usual skill.

Your roll can be hindered and helped. If you are hindered by an injury and helped by circumstances, for instance, you roll a d4 skill die and a d6 help die, and take the higher result. In other words, the only way to get a full success when you’re hindered, without any setback, is to also get helped.

Being helped by an ally uses their skill die for the help die. By the 24XX SRD rules as written, you’re typically only going to roll two dice at once—one skill die and one help die. If the help comes from circumstances, like attacking someone you’ve already slowed down, the help die is a d6. If the help comes from an ally, like them laying down cover fire, use their most relevant skill instead of the d6. 

You can and should hack this to your satisfaction. If you want a character to be able to benefit from situational help and an ally’s help, maybe they can roll 3 dice. If a group of allies all works together, maybe you take the highest of all their dice. If a situational factor is really helpful, maybe you prompt to roll something higher than a d6. If you’re making a hack where you want extra dice rules to emphasize certain themes, go ahead and add them. I’ve done all of the above myself in play (and with the stress die in 2400 Orbital Decay). 

Hope this helps, and feel free to ask if I missed anything or if you have any follow  up questions!

Thanks Jason!