My system is a simple 1d8 roll at/under:

skill levels are 1 - 7
a 1 is always a success
an 8 is always a fail
Roll at or under your skill level to succeed

because of some feedback in my playtesting for Waverly, I have come up with a few things to add, let me know if you like them.  If you don't know the game, I can send you a link to get a free copy from drivethrurpg if you pm your email.

Skills are increased with xp being spent (ie you can raise a 4 to a 5 as long as you have enough xp for the higher number).
What if you could purchase bonus die rolls like skills, so that a lower level character could get an extra chance to succeed with a roll?

Idea 1 - You can buy extra dice with XP, but they are a spendable stat:
Character purchases two extra die rolls.  They miss a strike in combat, so they spend a die roll to strike again.  Down to 1 extra die roll.  They fail a lock pick, and spend the last die to get a success.  They must now spend XP for more extra rolls during game play.

Idea 2 - You buy up to X extra dice as a skill, and can reroll any fail up to that amount each day:
Character has two extra die rolls.  Same information as before in idea 1, only the next day the die rolls reset to two, and no XP has to be used unless they want to buy a third die roll for their character.

Idea 3 - You can buy up to X extra dice as a skill, and can use up to that many rolls for any given action:
Character has three extra die rolls.  They fail at a lock pick, and roll again.  Another fail, and they roll again.  Success.  Next action is a disarm trap.  They have rolled once for the skill, and three times for the extra rolls all fails.  They cannot use any more rolls on this action.  Character can still use three extra rolls on any given action except that trap.

Idea 4 - Same as above, but the extra die rolls can be used for multiple successes:
In combat they make a Strike roll for 6 points of damage.  They roll bonus dice for two more successes giving 18 damage.  Next action comes with two successes, but a third roll fails.  All action then fail, so it becomes a miss with no damage.   (this way you have to chance losing all damage just to increase the damage delt.

Idea 5 - (last one)  Same as above, but you remove the restriction of losing all damage with a fail, and replace it with your rolls stop at a fail.

Which one would you prefer in a single die system?  Should it stay single die?

EDIT:  started out with combat, but wanted it to be useful in full game.

In most games players don't spend xp on boosting rolls. I've played a number of systems that allow it and never had anyone use it. Advancement is usually too important to my players.

Re-rolling per day is something likely to be abused. The GM will have to keep a tally.

Re-rolling per action seems like it will just bog things down to a crawl.

As a different thought, I'm a big fan of fatigue mechanics and I find that missed rolls are a great way to get the effect of fatigue and the players enjoy it to boot. Say you have a 3 as your target number but roll a 5. You'd take 2 points of fatigue (I use the label Stress) and pass your roll. You'd have to figure out what those points do, and how they hamper the players to the proper degree. If you get the balance right, they don't get overused.

What onix said as far as spending permanent xp to re-roll. Players won't use this option unless its life-or-death. It can also lead to downward spirals where characters that have poor stats for whatever reason (bad initial rolls, bad build decisions, crippling in-game events) spend XP on rerolls to keep up, thus losing advancement and getting further and further behind.

Idea 3/4 seem to be turning your system into a dice-pool game.

What "problem" are you trying to "solve" with this? I'm not sure _why_ you are looking at this other than "feedback".

Quote from: Tod13;919785What "problem" are you trying to "solve" with this? I'm not sure _why_ you are looking at this other than "feedback".

During the last beta test, new characters tended to never hit and "older" (artificially aged with higher stats) tended to never miss.

The combat system has not found stability yet.  It works in the fact that there is balance, but it seems to hamper growth with so many low level fails.

I understand low levels have to work harder for growth, but I don't want to have players give up because it is too difficult to earn XP.  (combat wise)

EDIT:  ONIX has a great point with fatigue points.  I could let players take damage to succeed or just add another stat to the character sheet

Quote from: rway218;919838During the last beta test, new characters tended to never hit and "older" (artificially aged with higher stats) tended to never miss.

The combat system has not found stability yet.  It works in the fact that there is balance, but it seems to hamper growth with so many low level fails.

I understand low levels have to work harder for growth, but I don't want to have players give up because it is too difficult to earn XP.  (combat wise)

EDIT:  ONIX has a great point with fatigue points.  I could let players take damage to succeed or just add another stat to the character sheet

Using 1d8 <= character skill level (and 8 always fails), if people start at skill 1, you've basically got 12.5% chance to hit/succeed. I don't think this can or should be addressed with "buying extra" stuff. If you want things to be easier, make them easier.

I decided in my game I didn't want that bad of a chance to hit or do things and made characters start at 75% in their area of specialty and 50% in other areas.

If you want to keep the 1d8 mechanic, can you do this with "skill modifiers" based on opponents? Goblins give a +5 to character skill, so your skill 1 character has a 75% chance to hit them? A dragon gives -4, so your skill 8 characters have 50% chance to hit?

I don't like dice pools, so I won't make weak suggestions there.

Alternatively, I will point out making "roll 2 and pick best" is a well-known mechanic that a lot of people like. Use roll 2d8 and pick the lowest, this gives you at most (according to AnyDice, if I did this right):

1    23.44%
2    43.75%   
3    60.94%
4    75.00%
5    85.94%
6    93.75%
7    98.44%
8     100.00%

That means 25% of the time you'll get a 1, 44% of the time you'll get a 1 or 2. If you make a starting skill of 2 possible for specializations, that gives you hits 50% of the time. Your higher level character still almost never miss. I'm OK with that myself. If you want to reduce that. maybe you can make the rules say if either die is an 8 you miss? (If I did the math right, that means automatic misses at 12.5%? I wish my wife were available, she's the statistician.)

I was going to say that a starting character shouldn't have any less than a 70% chance in their area of specialty. Tod beat me to it. I'd go as low as 30% in other areas unless they're supposed to be terrible at a task.