In the game I'm working on, players will have to roll skill checks vs. one of three possible skills in various situations. I'm leaning toward a simple d6 based system where the player rolls dice equal to the value of their skill.
I am debating whether to make passing rely on the sum of the rolled dice (e.g. players must have a total of 12 pips showing to pass), or making it a pass/fail per die (e.g. dice that show 4 or higher are success, must have n successes to pass test). I'm leaning toward the second option (pass/fail per die), but was wondering what values would be acceptable for passes and failures for either configuration, or what would be considered easy, medium, hard challenges.
FYI: Skills range from 2-6 currently, with the average being 3.33 across all characters. Each characters' stats sum to 10, meaning that some characters will have two very low stats and one high and some will be more balanced. There are no tests that require players to combine stats to pass, though some will require two separate checks. I also expect there to be challenges that certain players cannot pass without items/other mechanics.