My solution approach #2 for handling difficulty modifiers is actually inspired (kind of) by The Fantasy Trip (or their forebears Melee and Wizard), originally done by Steve Jackson of Steve Jackson Games. In these games you by default roll 3d6 for tests. For higher difficulties you roll 4d6 or 5d6.
Taking into account the basic rules I laid out (few dice) I will use a variant of this approach. In Gaia gamma (under solution #2) you roll
- 3dx-H for easy tasks where the uncertain outcome nonetheless should be determined by chance
- 3dx-L for hard tasks where the uncertain outcome in any case must be determined by Fate
- 3dx-H means: Roll 3d6, remove the highest die and multiply the other two to get the final score (e.g. 2, 3, 5 make for a score of 6 = 2 times 3).
- 3dx-L means: Roll 3d6, remove the lowest die and multiply the other two to get the final score (e.g. 2, 3, 5 make for a score of 15 = 3 times 5).
How do you like approach #2?