Generally speaking, you are always responsible for repercussions of your actions. If you don't take reasonable precaution to avoid hurting people you may be found at fault if your actions (or inactions) end up hurting someone.*
Some states (like CO) have laws that basically say 'all skiers are required to do the following: '. This establishes a "duty" that you must perform, and not following that "duty" may automatically put you at fault (at least partly). Of course, if the list of rules is vague then you can argue about whether you actually were in violation of them.
I was going to hit the slopes for my first day and couldn't, so this needs to keep going.
That first part about reasonable precautions isn't complete. You can only be negligent if you had a duty of care. No duty of care, no precautions, no reasonableness standard.
I used CO as an example hundreds of posts ago. The code is not incorporated in Colorado's Ski Safety Act and has no legal bearing at all. Common law negligence also has no bearing - we have a specific statute that defines duties as you point out, and this is classified as 'Negligence Per Se', which is a strange way of saying that only the statute is assigning duty of care as prescribed by the legislature (no common law interpretation) unless the claim can be found to be outside the statute (see the Vail thread re: avalanche not as an inherent risk of skiing, subjecting it to the common law standard of negligence and outside the limitation of liability cap).
Colorado's ski act is clearer than the code. It states:
Breaking the first sentence down into its parts we get:
1) Each skier has the duty to maintain control of his speed at all times when skiing so as to be able to avoid other skiers and objects.
2) Each skier has the duty to maintain control of his course at all times when skiing so as to be able to avoid other skiers and objects.
3) Each skier has the duty to maintain a proper lookout so as to be able to avoid other skiers and objects.
Each of these puts a burden of duty on downhill skiers. #3 puts exactly the burden contemplated by the OP on downhill skiers. #2 certainly means more than "don't lose control", because that statement fails the reasonableness test outright (it is purely aspirational). There is no reason to use the word "course" unless there us a duty to assess course so as to avoid other skiers, although some have disagreed and seem to think #1 & #2 do not incorporate the part about "so as to be able to avoid other skiers and objects".
CO puts the primary duty on the uphill skier. Primary duty does not appear to have a defined statutory meaning...it seems to be intended more as a weighting factor given all states recognize the concept of contributory negligence. This means that a plaintiff's own negligence may have contributed to the harm he suffered by the defendant's negligence. The idea is that we all have a duty to act in a reasonable prudent manner. In straight contributory negligence, if the plaintiff can be found to have been negligent to any degree, then she is barred from any recovery. The great majority of states have recognized that this can lead to unfair results - if it is 10% me and 90% you, then my 10% bars me from recovering the 80% where you were 'more negligent than me'.
Those states have adopted some form of comparative negligence standard, which is designed to allocate negligence between the parties. Colorado uses a "Modified Comparative Negligence" standard, which means that the plaintiff cannot recover anything if she has equal to or greater degree of negligence than the defendant. For those wondering why Vail claimed that the boy killed in the avalanche case was negligent, this is why.
I think Colorado assigns a primary duty to the uphill skier in Tog's original Grey/Red video precisely to break the tie when both skiers otherwise fail their duties, acknowledging that the uphill skier is in a better position to avoid. I don't see how Colorado's law can be interpreted to mean anything other than a downhill skier can negligently contribute to his own harm, but it would probably have to be reckless for her to be 'more negligent' than an uphill skier.
I still think Colorado got it right.