Pathfinder Reboot Codex: House Rules

Perception and Knowledge

Perception checks work with some significant differences in our house variant rules. Instead of placing ranks in the Perception skill, when the GM issues a challenge related to observing something hidden or subtle, characters may roll a d20 to perceive. Outside areas of their experience, characters have a base 10% chance (a roll of 19 or 20) to spot the inconsistency. If actively seeking, this chance increases by 5% for each minute spent in search.

If the character is experienced in the area, they have a base 30% chance to spot inconsistencies (roll 15-20 for success). If actively searching this increases by 10% per minute, or may simply result in immediate discovery.

Experience in a field of perception may relate to the character’s class, race, skills, feats, background, or adventuring history. Encountering a similar situation in the past prepares a character to observe such subtleties in the future. Experience is granted at GM discretion, but players can make the case why their characters should be considered experienced in a given situation at any time.

Knowledge Skills

Knowledge grants experience (as defined above), and experience grants knowledge. If you have a knowledge skill in a particular area, odds are very good the GM will rule you have experience in that area for the purposes of perception checks. Likewise, if the GM rules that your character has experience in an area, odds are you have some knowledge of it and can roll checks based on that knowledge to bring information to mind that is relevant to the topic.

Unlike perception, ranks in knowledge skills are worth having.

Also noteworthy in this regard: training in non-knowledge skills confers some knowledge of topics related to the skill. Often this will be very specific (“does this cliff look climbable?”) but if you can propose a creative use for the knowledge a skill confers, the GM may allow it (“I’d like to use my experience as an Escape Artist to see whether it looks like he’s faking the knots on the ropes holding him.”) There are some special cases to this; see the note about Knowledge: Arcana below, if you’re a spellcaster who likes detecting magic.

Detecting Magic

Ahh, good old Detect Magic. As a cantrip, it’s effectively been reduced to the CRPG minimap radar ping of Pathfinder. Because of that, we’re changing how it works a bit for our campaign.

The cantrip still works as advertised the first round you cast it: you get a “yes/no” answer to the question “is there magic in the direction I’m facing (60° arc, out to 60 feet), or in the item I’m examining?” Notably, doing a 360° sweep to yield this binary information takes six rounds (36 seconds) to complete.

If you would like more information than this, house rules start kicking in: the concept of experience as outlined above works similarly when detecting magic. As you hold your detection on a single object or direction into a second round, the GM will ask what sort of magic you’re looking for. You can describe it either by the effect you think it might have (“I think this might be cursed”, “I’m looking for runes or wards”) or by naming a school of magic. The GM will then ask how you’re experienced with this type of magic.

Your ability to detect the type of magic you seek depends on your experience with it. Experience in magic can come from your class, race, background, spell portfolio, or Knowledge skills, and it’s your responsibility to keep track of the types of magical effects your character is familiar with. Knowledge – Arcana is no longer a catch-all for this: to round out your magical knowledge, you’ll have to place ranks in the various schools or effects you want to study (“Knowledge – Transmutation”, “Knowledge – Curses”, “Knowledge – Illusion”, “Knowledge – Pyromancy” are all valid options).

Knowledge – Arcana still functions as knowledge of magic in the world and the ways it works.

If you’d like to detect the exact name and nature of magical items, Appraisal and other knowledge skills will come into play.

As an alternative to the above, you can cast Detect Magic by powering it (with a custom metamagic feat) to the level of more potent Divination school effects; this consumes a spell use at a higher level equivalent to the power of the divination effect you’re trying to achieve. Identifying a magical item cold (with no supporting knowledge or experience) is the equivalent of a 4th level spell.

Detecting Evil

Evil exists in the world. Unfortunately, it’s not so easy to root out as casting a level 1 spell. Most of the time, you’ll have better luck determining a person or creature’s intent using the Sense Motive skill (or simply judging them by their interactions with you).

Most evil is far too mundane to be discovered by the Detect Evil spell. However, it still functions in the case of supernatural evil: creatures native to planes defined ideologically by pure vileness or creatures ancient or alien enough to possess inhuman moral codes will glow like rotten beacons to the eyes of a good-aligned cleric or paladin. Thus, the spell retains some usefulness in discovering such creatures who hide their identities (via polymorph, for example), and it grants the wielder the experience bonus to perception when observing them without the aid of the spell.

In addition, another category that the spell detects (at GM discretion) is that of the most devout mortal followers of evil deities or ethea. High level clerics, antipaladins, oracles, and other divine spellcasters become akin to outsiders in the purity and extraordinary nature of their evil, as do even higher level lay worshippers (warlords, generals, and kings). Conversely, party members (or others) who attain high level in good-aligned classes will be much easier to spot for anyone using the Detect Good spell.

Critical Hits and Critical Fumbles

We’ll start the campaign using variant crit rules associated with the Critical Hit and Critical Fumble decks from Paizo.


The threshold that triggers use of the cards is something we’ll feel out through play (this post will be updated as more detailed conventions are adopted).


With (at least) five of our party members able to invoke arcane or divine power, there is going to be a LOT of magic in this campaign. This is a good time to refresh ourselves on some of the more snarly bits of magic-related game in Pathfinder:

  • Concentration Checks — These are a thing! All of our casters are Charisma-based, so to make a check, roll d20 and add your caster level and your Charisma bonus (and any applicable feats or other abilities). You’ll have to beat a DC of 10 + the level of your spell if jostled, or 10 + damage taken + the level of your spell if injured.
  • Spell DCs
  • Armor Check Penalties — These are a thing! If you’re wearing mundane armor and attempting to cast spells with somatic components, you have a chance of failure as listed in the armor’s description. This can be avoided by casting spells without physical movement requirements, or by using a metamagic feat to cast a spell that normally requires movement without it.
  • Spell Components (Verbal, Somatic, Material, Focus, Divine Focus) — These are all things! If you don’t have the proper components or are otherwise impeded from casting a spell that requires them, the spell will fail. Metamagic feats can circumvent this.
  • Metamagic Feats – All spellcasters have access to all metamagic feats in the game for free. Costs of using the feats (in spell levels added) and effects of the feats are unchanged.
  • Counterspells – I’d like to figure out a new, more streamlined system for this.

Gear, Encumbrance and Practical Life

In this campaign you’ll be earning every piece of gear, every item, and every gold piece you acquire. Your characters will become hungry and thirsty, and may become exhausted or sick if overexerted. I won’t be a stickler for precise encumbrance rules, but items you carry — including currency — will have mass and weight. You’ll have to figure out where to stash your stuff, or how to get rid of it, if you accumulate too much to realistically cart around with you.

As with real life, using items you find in your environment to deal with challenges may sometimes be the only way (or the most practical way) to resolve them.

Leveling Up

Max HP are received at level up; no more die rolling. Elements that contribute to HP at level up:

  • Class Hit Die
  • Constitution Bonus
  • Favored Class Bonus (if leveling in a favored class and opting for 1 HP over 1 skill point)
  • Toughness Feat

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