Diminishing Returns
When using diminishing returns it is possible to hit a point where a DC becomes arbitrarily high but the check remains possible due to the DC automatically diminishing down to 30. These rules are intended to alleviate that discrepancy and make certain checks impossible for all but the most proficient or powerful. At each tier of play there is a Maximum DC threshold that characters can attempt pt. This represents an approximate gate of what should be generally possibly of someone of their power level and maintain some level of verisimilitude. For example level 1 commoners shouldn't be capable of breaking open manacles in 20 attempts (the DC 26 break DC becomes a DC 20).
Table 1-1
| CR | Max DC | |
|---|---|---|
| 1-5 | 25 | May attempt any DC of 0 to 25 |
| 6-10 | 35 | May attempt any DC of 26 to 35 |
| 11-15 | 45 | May attempt any DC of 36 to 45 |
| 16-20 | 55+ | May attempt any DC of 46 to 55, special |
Refer to table 1-1 for the maximum DC for a given level. A character normally cannot attempt a DC greater than the corresponding "Max DC" for their given level, with one exception. If the characters diminished modifier + 20 would be sufficient to beat the undiminished DC they may roll the check, using diminished values for both the DC and roll modifier. If a characters level is greater than that of the DC then the roll is diminished regardless of their modifiers.
This allows characters who are truly exceptional at a check to preform feats which would otherwise be for all intents and purposes impossible. This also gives a sense of heroic progression as characters level up tasks that were seemingly impossible before become significantly easier.
Example 1
A 1st level character wants to break out of his manacles, but his diminished strength modifier is only a +5 , meaning he cannot break out of the manacles. However If he could raise his diminished modifier by 1 to a +6 then he could roll 1d20+6 vs DC 20 to try and break out. However a 6th level character could attempt the roll regardless of their modifier
In the case of truly massive DC's in excess of 55 are handled differently but are still subject to the previous rule. i.e if the number would be in excess of the characters Maximum DC threshold they still must have the minimum modifier. If a DC is in excess of 45 compare the undiminished values of each. If success is possible then the roll can be attempted using diminished values, do not cap the DC at 30 or the roll bonus at 20.
Example 2
A 16th level character wants carve a path under the mountain in order to get to their destination, but they are pressed for time So they want to work increase their speed to 1 5 foot cube of material per standard action, DC 15 + 50 = 65. Because they are level 16 there is no cap on the DC they can attempt so all they need is a +45 undiminished modifier to their mining check. Assuming they have exactly a +45 they can roll 1d20+25 vs DC 40. Not an easy feat! However if they lowered their target to a DC 55 (1 cube per round instead of per standard action) then the DC would cap at 30 meaning they can tunnel away by just taking 10.
This rule does not apply to non-binary or opposed rolls (such as fly checks, diplomacy checks and opposed skill checks).
This rule does apply to saving throws, meaning it is possible that a spell may be irresistible to lesser foes.
This rule does apply to Armor Class. If the Attacker's resting bonus is not high enough to beat the defenders resting AC then the damage dealt is reduced by 50%, this amount increased by 25% for every tier between the attackers bonus (or tier) and the defenders AC.
Resting AC and To Hit is defined as AC and to hit without any temporary buffs or de-buffs to the modifier/DC, like power attack or combat expertise with 3 exceptions:
- Spell buffs for which the character has the internalize spell feat.
- Iconic class features such as Barbarian Rage, Bardsong, Ranger Quarry.
- The Rogue uses his level in place of his BAB when determining his effective attack bonus.
Example 3
A Character tries to attack the Tarrasque (AC 40, Tier 3). If he is level 1-5 He needs at least a +6 Diminished bonus in order to do damage. If he hits (+6 or more vs AC 27) The Tarrasque takes 75% reduced * damage before any other mitigation. If He can raise his bonus to a +15 then the Tarrasque takes 50% damage. And if he can somehow get a +20 then The Tarrasque takes full damage. If he is level 6-10 The Tarrasque always takes at least 50% reduced damage regardless of his modifier and takes full damage if the character has at least a +15 If he is level 11+ the Tarrasque always takes full damage regardless of his modifier.