I'm something of an advocate for the idea that if the PCs have a 95% chance of succeeding on any roll the DM throws at them, then the DM isn't doing his job. Of course, the cost of failing a check in a game of Rocket Tag is usually death. Now, there are abilities that somewhat remedy this such as Action Points, but I don't like the un-reliability of any of the Action Point systems. As such, I'm going to try my hand at crafting something a little different: PCs having the option to just plain fudge their dice. Within limits, of course.
This requires some ground rules first, however:
1) Start by using the Bell Curve system. While it shrinks the RNG, it also mitigates IP somewhat. What's more, the premise is that the DM is supposed to throw enemies at the players that present challenges significantly inside of the range of the RNG, anyway, and using 3d6 instead of 1d20 allows the flexibility needed for the meat of my idea. (Note: I'm not changing Take 10 or Take 20, including the numbers on Taking 20, so you basically get an extra +2 bonus when you're really careful.) The system also works much better if you have the players rolling all of the dice (see the UA variant). If you're not interested in that, then you can have the players substitute inverted values in order to maintain the same objective value of a given die.
2) I'm already toying with the idea of changing up the leveling system, and this will provide something nice to give on alternating levels. I'm thinking of giving a feat at first level, second level, and every even level thereafter, while PCs get something called a "Boon" at first, third, fifth, etc. levels. Under this system, they don't gain ability score bonuses, but those are addressed by the boons. The ones I have right now are modeled after Luck feats, and, as such, Luck feats won't be in the game.
Now, the meat of my idea:
All PCs have what's called a Fate score. By default, this score is equal to 1 + 1/2 the PC's level (rounded up). Certain things can boost the PC's Fate score, like the Luckblade (+1 Fate score, instead of granting it's daily reroll), and the Luck domain (+1 Fate score and a bonus Boon, instead of it's normal ability). The primary function of this Fate score is that, at the beginning of each day, you roll a number of d6's equal to your Fate score and record the results, later known as your Fate Dice. Later on during the day, you can discard a Fate Die before making a 3d6 roll to instead roll 4d6 and drop the lowest roll. Boons give you more uses for your Fate Dice, such as allowing you to substitute in your recorded dice for rolled dice (Attack Rolls, Saving Throws, Skill Checks, etc., not stuff like Fireball damage) and treat the natural roll according to how it's been altered, or discard dice altogether to gain more powerful effects. How you are able to do this depends on your Boons.
Boons follow the same general conventions as feats, but cannot be taken as feats and cannot be substituted for feats. You cannot use a Boon on the same roll you discard a Fate Die to alter. Boons are as follows:
Destined StrikeBenefit: Whenever you make an attack roll against a hostile target, you can substitute one of your Fate Dice for one of the dice in your attack roll. The value of the Fate Die replaces the value of the rolled die, and vice-versa.
Fate-Spurned StrikePre-Requisite: Destined Strike
Benefit: Whenever you make an attack roll against a hostile target, you can discard a Fate Die with a value of 5 or 6 to reroll the attack roll.
Destined DeflectionBenefit: Whenever a hostile enemy makes an attack against you, you can substitute one of your Fate Dice for one of the dice in your armor class roll. The value of the Fate Die replaces the value of the rolled die, and vice-versa.
Fate-Spurned DeflectionPre-Requisite: Destined Deflection
Benefit: Whenever a hostile enemy makes an attack against you, you can discard a Fate Die with a value of 5 or 6 to reroll the armor class roll.
From the 4 boons above, imagine appropriate text for each of the following types of rolls:
Saving Throws (Destined Tenacity)
Spell Resistance (Destined Resistance)
Spell Save DCs (Destined Assault)
Caster Level Checks (Destined Spell)
Initiative Checks (Destined Foresight)
Strength checks and Strength-based skill checks (Destined Might)
Dexterity... (Destined Agility)
Constitution... (Destined Fortitude)
Intelligence... (Destined Revelation)
Wisdom... (Destined Insight)
Charisma... (Destined Influence)
Tenacity of the BeastBenefit: If you roll a natural 3 on a saving throw, you can discard a Fate Die with a value of 1 to treat the roll as a natural 18 instead.
Vengeance of the BeastBenefit: If you roll a natural 3 on a Save DC roll, you can discard a Fate Die with a value of 1 to treat the roll as a natural 18 instead.
Ferocity of the BeastBenefit: If you roll a natural 3 on an attack roll, you can discard a Fate Die with a value of 1 to treat the roll as a natural 18 instead.
Cunning of the BeastBenefit: If you roll a natural 3 on a skill check, you can discard a Fate Die with a value of 1 to treat the roll as a natural 18 instead.
Endurance of the BeastBenefit: If you roll a natural 3 on an armor class roll, you can discard a Fate Die with a value of 1 to treat the roll as a natural 18 instead.
Enduring LegendBenefit: Your Fate score increases by one.
Special: You can take this boon multiple times. It's effects stack.
Better Good than LuckyBenefit: One ability score of your choice is permanently increased by one. Your Fate score is decreased by one.
Special: You can take this boon multiple times. It's effects stack.
Accumulation of DestinyBenefit: At the beginning of an encounter, if the number of Fate Dice you possess is less than your Fate score, you may roll a d6 and record it's value as a Fate Die.
Questions, Comments, or Criticisms? Glaring omissions, possibly?