Contribution (cf. fault)
Contribution is a non-judgmental word of assessment. I say X contributed to Y happening or not happening. And I can assert that the contribution happened because of a certain factor related to X or X's behavior. For example, I can say that that driver X contributed to driver Y getting a broken neck by X driving their car in such a way as to ram into the back of Y's car at a specified speed. I can say that driver Y contributed to the result of their neck getting broken by not wearing a seat belt at the time of the crash. For any given result or set of results, most often there are many contributing factors, any one of which, if it did not exist, would affect whether or not the result occurred, even with the other factors remaining the same. The word contribution can apply to factors that are instrumental in outcomes, which can be either desirable or undesirable.
In contrast, I use the word "fault" as synonymous with blame, which usually focused on one factor, most often a specific person or group of people, as if the other factors did not exist or did not matter. Fault is used in circumstances where the outcome is considered to be undesirable.
Fault may be used by some to indicate only contribution, but more often it is used to assign blame.
Fault requires that someone be identified as the perpetrator and another or others be identified as the victim. Contribution does not include the distinctions of perpetrator and victim.