The following is an expansion of the Base Stat rules first outlined in the 3.P Gameplay House Rules. These rules replace those for Base Stats, Base DC changes, Environmental Rules, and Immunity Changes.
At each level of a campaign, the GM(s) calculate the average gameplay statistics for player characters in all groups. These averages are referred to as Base Stats. As the Base Stats represent the average gameplay statistics for all player characters, they're a good baseline for the overall power level of the players at that level.
For the current base stats, see here. You'll notice that in addition to the Base Stat averages, we also calculate upper and lower bounds for certain stats. These are the Base Stat Bounds, the lowest and highest values that we allow for d20 rolls. For example, if the Base Stat for a save is +19, then the lower bound would be +10 and the upper bound would be +28. If a player character were to have that save at less than +10, they would automatically increase that save bonus to +10. Likewise, if they had a save bonus over +28, they would automatically decrease that save bonus to +28. This means that a nat 20 roll from the lower PC would exceed a nat 1 roll from the higher PC (30 vs. 29 respectively), giving them at least a slim chance in a head-to-head matchup. We apply these Bounds to NPCs as well as PCs.
These Base Stats assume that the characters are unbuffed (that is they haven't cast any spells or used any abilities to increase their stats temporarily). If the characters are buffed, different Base Stats are used with different Bounds. Note that the Buffed Base Stat Bounds represent the absolute ceiling for stats in the game: no encounter demands PCs with higher stats than these. Any further optimization is a waste. Players are strongly encouraged to keep their stats relatively close to that of other PCs, and these rules were introduced because we understand that it's easy to accidentally over-optimize.
However, we also recognize that pushing the limits is part of the fun of the game, and so rather than just strictly limit each PC to the stats, we're allowing a single Unbound stat per PC. For example, if your character is an Avatar of Strength, you might want your CMB checks for grapples to be Unbounded. This would allow these checks to exceed the Buffed and Unbuffed Bounds listed for CMB. But only those checks. CMB checks made to trip would still be Bound, for example. In some cases, multiple niche or obscure stats can be Unbounded. For example, Appraise and Escape artist are relatively obscure skills, so we'd allow both stats to be Unbounded if a PC asked (and they didn't abuse it). But Perception is one of the most frequently used skills, so we'd only allow that as the single Unbound stat. Feel free to discuss with the GM(s).
Some stats, like damage, aren't d20 rolls and thus don't have natural Bounds. In those cases, we recommend certain limits, but players don't strictly need to abide by these. In general, we recommend keeping your damage below your HP - after all, you wouldn't want to meet your twin who can one-shot you! It should be noted that some encounters will be completely Unbounded - these aren't encounters that PCs are ever intended to play as part of the normal difficulty curve of the campaign, but we'd like to leave the possibility open in case y'all decide to challenge Cthulhu or something. The GM(s) will announce such encounters when they begin - effectively suspending the Base Stat Bounding rules for the duration.
How Unbuffed Base Stats are calculated: We consider a single PCs Unbuffed Base Stats to be whatever stats they can maintain for the majority of encounters a day. So even if they're using a spell to increase a stat, we consider that an Unbuffed Base Stat if they can maintain it for 24 hours or at least long enough to cover most encounters (say 8 hours). This also applies if a PC has short-duration buffs of nearly infinite uses per day and can access them easily (say without an action, or just before every battle). Basically, if it doesn't take any significant resources (including action economy), then we consider it part of your Base Stats. If there's any confusion, ask the GM(s).
How Buffed Base Stats are calculated: We don't have as much data on exactly how much each stat is buffed, so until we do the Buffed Base Stats are considered to be just +10 from their Unbuffed versions. This means a couple of things. First of all, the average PC receiving a +1 to a stat will by definition be at the lower Bound of the Buffed Stats. This should give plenty of room for a variety of bonuses from yourself or other PCs. Generally, buffs from NPCs don't count toward buffed stats, nor do fate points, but everything else does. Make sure to apply the Buffed Bounds after all other modifications are made; apply Bounds last after any buffs. For example, if you give yourself +20 to a skill temporarily, that will likely push that skill all the way to its upper Bound. Any other buffs to that skill would be wasted. Another implication of this is that even a small buff to a stat can dramatically increase a PC's stat. For example, suppose that you have +10 stealth on your sheet. The lower bound for unbuffed stats is +21. So without buffing you'd effectively have +21 stealth. Now with a single +1 buff to stealth, you'd have +31 stealth, since that's the lower bound for buffed stats. Generally, you never apply buffs directly when using Base Stats, so there's no way you'd roll a +22 stealth above.
How Base Stats for skills are calculated: We only bring a skill up to its lower Bound when a PC has invested full ranks in the skill. The idea is that if they've made a practical effort to improve the skill, then they should at least be within throwing distance of PCs that have heavily optimized in it. This increase, however, does not apply to skills with fewer ranks. That applies to both Unbuffed and Buffed lower Bounds. So in the example above, the character would only receive the benefit of increasing to +31 stealth if they have max ranks in stealth already. With anything less they'd remain at +10 stealth (plus any normal bonus provided by the buff).
How related Base Stats are calculated: Many stats are closely tied to one another, such as attack and AC, CMB and CMD, saves and DCs, etc. In order to maintain game balance, the Base Stats have been modified slightly from the true PC averages such that these linked stats are kept roughly equal. Generally, we've increased the lower stat to match the higher stat. Special note should be given to DCs: of all the PC stats, DCs have historically been very low (they're difficult to optimize). This means that for most characters, these rules represent a general buff to their DCs. See the discussion below for how to calculate new DCs using these Base Stat Bounds.
Environmental Rules: Environments are more deadly in the World of the Ledge. Among other changes, the maximum damage that environmental hazards can inflict increases to the upper Bound suggested for unbuffed area damage (~240 currently at level 10). This applies to fall damage, contact with lava, intense pressure, and similar extreme environmental conditions. Supernatural hazards might use buffed area damage instead. Players are advised to tread carefully.
Base DCs: Many DCs are quickly outpaced by high-power characters in Tiered Gestalt. To allow for at least some chance of failure, the DCs for effects that are not a function of character statistics have been increased. This includes the DCs for environmental effects, as well as poisons, and a number of other incidental abilities.
This does not apply to ability checks, level checks, or similar. Nor does it apply to spell DCs or the DCs of most supernatural abilities (as they're a function of a character's level and ability scores). The GM still has discretion in raising or lowering DCs.
Some DCs are technically based on a character's statistics, but they don't scale appropriately. For example, the DC to demoralize a character doesn't scale well with the intimidate skill. In these cases, characters can benefit from DCs based on skill averages (generally +10 from skill Base Stats, or whatever other statistic the DC should be scaling off of).
To determine whether a spell or ability of a character should benefit from being increased by a lower Bound, use the following criteria:
Immunities: Immunity to effects now functions as superior resistances:
Additionally, sentient undead, constructs, and other creatures normally immune to mind-affect effects by nature of their creature type are no longer immune to mind-affecting effects. To be considered sentient, the creature must have an Intelligence, Wisdom, and Charisma score of at least 3. All the changes listed above apply equally to mythic and non-mythic effects.
The following feats aren't finalized, but rather topics for consideration.
Benefit(s): Choose a Base Stat from among the following:
Initiative, AC, Touch AC, Flat-Footed AC, CMD, Flat-Footed CMD, SR, Fortitude saves, Reflex saves, Will saves, Melee Attack Bonus, Ranged Attack Bonus, CMB, or a single skill.
If your stat is less than the corresponding unbuffed Base Stat's average, then you may substitute the unbuffed Base Stat average for rolls associated with that stat. For example, if your Will save is +9 on your sheet, and the unbuffed Base Stat average is +19, you may roll Will saves with a +19 instead of a +10 (the unbuffed lower Bound).
Special: Your chosen Base Stat will no longer be used to calculate general Base Stats in the future.
Prerequisite(s): Base Stat Focus.
Benefit(s): Choose a Base Stat for which you've already chosen Base Stat Focus.
If your stat is less than the corresponding Base Stat's unbuffed upper Bound, then you may substitute the unbuffed upper Bound for rolls associated with that stat. For example, if your Will save is +9 on your sheet, and the unbuffed upper Bound is +28, you may roll Will saves with a +28 instead of a +10 (the unbuffed lower Bound).
Prerequisite(s): Improved Base Stat Focus.
Benefit(s): Choose a Base Stat for which you've already chosen Improved Base Stat Focus.
If your stat is less than the corresponding Base Stat's buffed upper Bound, then you may spend a fate point once per day (no action) to substitute the buffed upper Bound for rolls associated with that stat. For example, if your Will save is +9 on your sheet, and the buffed upper Bound is +38, you may spend a fate point to roll a Will save with a +38 instead of a +20 (the buffed lower Bound).
Benefit(s): Choose a single spell or ability that allows for a saving throw or check against a DC.
If the spell or ability's DC would be less than the unbuffed High DC Base Stat average, then you may substitute the unbuffed High DC Base Stat average for rolls associated with that spell or ability. For example, if your ability's DC is 19 on your sheet, and the unbuffed High DC Base Stat average is 29, you may treat that ability's DC as though it were 29.
Special: This feat can only be applied to a single spell or ability, and this decision cannot be changed. The spell or ability likewise cannot be altered by metamagic, additional talents, or similar changes to the DC.