Adjust difficulty without affecting character's capacity, without adding steps to assess result, for a dice pool with unvariable target system

Question

I'm searching for alternatives to adjust the difficulty for a count success system with a d6 or d10 dice pool, where characters' stats form the pool (ex: dext 3 + guile 3 = 6 dice pool).

The ways I do not want to use:

1. remove dice from the pool
   • example: "it is hard, remove 2d from your pool"
   • pro: applied before the rolls, so the result of the roll will not be modified afterwards, making assessment of the result faster
   • con: increase % of failure, while I only want to decrease the likelihood to happen, not the capability of the characters
   • con: the psychological effect is "unfair" (for my players at least)
2. changing the number of successes required
   • example: "it is hard, make 3 successes instead of 2"
   • pro: does not increase % of failure
   • pro: the psychological effect is "fair" (to make more efforts)
   • con: it makes the system variable (in the example, 2 would be no more a full success but a partial success; while I want 0 successes = always fail, 1 success = always partial success, 2 successes = always full success...)
3. changing the pip that qualify as success
   • example: "it is hard, successes are 6 instead of 5 and 6"
   • pro: does not increase % of failure
   • con: it makes the system variable (in the example, 5 would be no more a success; while I want 5, 6 always to be successes)
4. to remove success after the roll
   • example: "it is hard, remove 2 success from the roll"
   • pro: does not increase % of failure
   • con: modifier is applied after the dice rolled, so it slows the assessment of the result
   • con: the psychological effect is "unfair" (for my players at least)

What I tried (only applied if task is inherently hard):

• any 1 in the result automatically makes it a partial success but it is not good because the bigger the dice pool (meaning competent), the bigger the chance of rolling 1s
• to add "difficulty dice" in the players' pool, where 1 on those dice makes it a partial success, but it slows the assessment of the result and I prefer to avoid to add stuff like different dice, cards, tokens...
• to make 2 success merge as 1, but it slows the assessment of the result and it is not elegant for 3 successes (merged as 1 or 2?) or 5 successes (merged as 2 or 3?)
• to reroll and take the lowest result, but it slows the game

Answer 1

Reroll only successes or only specific numbers.

So if the player rolls 2,2,4,5,5,6 for a "hard task" he would have to reroll the two 5s and for a "very hard task" he would have to reroll all three successes. One could say "you have to verify the successes".

For easy tasks you could allow rerolling 1s for example.

This should be faster than rerolling the full pool and taking the lower result, since you don't have the hassle to count and memorize the first roll.

From the explanation of the ways you don't want to use, I would guess that this method should "do not increase % of failure" and "the psychological effect is "fair" (to make more efforts)"

Note however that this method decreases the chance of success for "hard tasks" tremendously. So I personally would adjust the default success threshold from 5+ down to 4+ for this method and then have four difficulty levels at hand: No rerolls, 4 has to be rerolled, 4 and 5 have to be rerolled and all successes have to be rerolled.

Answer 2

I don't understand what "con: it makes the system variable" means. In order to "adjust the difficulty" you need to vary something!

IMHO a simple solution is "this is a difficult task, only 6es are success" or "this is an elementary task. 3 and above count as a success". This way you can have a constant table of what does each number of successes mean:

I want 0 success = always fail, 1 success = always partial success, 2 success = always full success...

I find this setup intuitive as higher threshold == more difficult task, more difficult to succeed. More successes == more of a (spectacular) success.