Taking a stab at a rough draft for my Perception = Saving Throw house rule. Pretty sure I want to try some version of this in my next campaign, but definitely excited to hear your feedback, critique, and comments. I tried incorporating some of the feedback you graciously offered into this rough draft. Without further ado...
Perception Saves
Perception is no longer a skill that PCs actively use. Instead, it is a saving throw which helps with noticing ambushes (avoid surprise) and traps at the last minute (quick reaction as the trap is triggered). It has no associated ability score by default, but all PCs apply their proficiency bonus – a minimum competence of all adventurers is awareness of hidden dangers. Think of it as a “hidden danger saving throw.”
A PC who would gain Perception as a “skill” due to their race, subclass, background, or feat can apply either their Wisdom or Intelligence modifier to their Perception saving throw.
When a character takes time to explore an area or uses the Search action, the GM says what they discover. The GM is forthcoming and offers clues that foreshadow hidden things.
There are a few considerations about how this interacts with other rules:
- Advantage – If anything would grant you advantage on a Perception check, you instead gain advantage on your Perception saving throw.
- Bardic Inspiration can be applied to Perception saves.
- Dim light imposes disadvantage on Perception saves relying on sight.
- Expertise cannot be applied to Perception saves.
- Feat (Dungeon Delver) grants advantage on Perception saves against traps, and advantage on Investigation checks to determine a secret door’s mechanism of action (instead of on Perception & Investigation checks to notice secret doors).
- Feat (Observant) grants advantage to Investigation checks and Perception saves made in well-lit conditions (instead of +5).
- Feat (Skulker) negates disadvantage on Perception saves due to dim light.
- Magic Items vary in whether they apply to Perception saves: Cloaks of Protection and Rings of Protection do not. However, a Luck Blade, Robe of Stars, Rod of Alertness, Staff of Power, and Stone of Good Luck does apply the save bonus to Perception.
- Paladin’s Aura of Protection does not apply to Perception saving throws; the paladin’s aura is about resolve, not foreknowledge or awareness.
- Rangers may select Aura of Awareness instead of Hide in Plain Sight and Vanish; this aura grants a bonus to Perception saves.
- Spells that boost saving throws, like Bless, can be applied to Perception saves.
And here's the design intent, reposted/edited for clarity:
- Separate GM description, asking questions, and players trying things from Danger perception.
- Remove need for GM to track passive perception.
- Distinguish Perception and Investigation. Perception is your instinctive response when something has gone pear-shaped and you’re in immediate peril. Investigation is figuring out how things work, such as the mechanism of action for a trap or secret door.
- Circumvent habits of some players who ask to roll Perception, and encourages engaging with the fiction.
- Rein in rampantly high Perception checks, to keep them more in line with the Stealth scores of monsters and trap save DCs.
