Since Skids rerolls all 1s, and Composed lets you rerolls all dice if you don't roll any 1s, can he reroll endlessly until he succeeds as he needs?
Let's look at the exact wording on the cards:
Whenever you roll a 1 during a test, you may reroll that die.
When resolving a test, if you do not roll any 1's, you may reroll all of your dice.
You can trigger Skids' ability whenever you roll a 1 during a test, that is apparent.
Composed on the other hand is triggered while you are resolving the test. If you have no 1's at this point, you can choose to reroll all dice.
From the Rules Reference:
If a Condition's effect does not list a limit, it may only be used once per instance of the triggered event.
As this is rolling dice during a single test, you can use Skids' ability to reroll any 1's again, but you are still in the resolving the same test, and you can not trigger composed again.
- Skids' ability can be triggered during any roll during a test
- Composed can be triggered once per test
Therefore you can not roll endlessly until you succeed, but it certainly is a good combination that would lead to greater chance of success.
There is also a discussion of this combination on BGG