Perception vs Passive Perception

[TwinBahamut]

I believe Gargazon has it right.

No matter what you are doing, you have a chance to see something with your passive Perception score. If you walk into a corridor that has a trap, anyone with a passive Perception score high enough to see the trap will simply notice it without needing to roll anything. However, if no one actually has a high enough modifier to see it passively, they still have a chance to see it when they actively look around for traps. You only roll for Perception when you say "I look around for something", and otherwise it is covered by passive Perception.

I rather like the idea that characters no longer have to worry about rolling a 1 on a spot check and completely failing to see something obviously visible in the middle of the room (something of an exaggeration, but still...).

 

[mach1.9pants]

You've lost your car keys and need to find them desperately. You have searched all over the house, living room, kitchen, room, bathroom, etc. You can't seem to find them. You give up and call a friend for a ride.

You head into the kitchen to grab yourself some orange juice before your ride arrives. As you pour yourself some OJ, you notice, out of the corner of your eye, the keys. They have been laying on top of the kitchen counter all along.

In that scenario your active Perception roll was lower than your passive Perception roll.

That is called 'Male Pattern Blindness' or 'Domestic Blindness'; well so my wife tells me when I can't find something right in front of me

 

[Moon-Lancer]

ok, so if I understand this. A character has one rank, Perception. and active and passive are just ways they are used?

 

[DandD]

Yes, it seems so.

 

[Gargazon]

ok, so if I understand this. A character has one rank, Perception. and active and passive are just ways they are used?

If by rank you mean skill, yes, that is how it would appear to work. The same will be true for insight, I believe.

 

[Moon-Lancer]

yes, i misspoke i meant skill. If thats true I really like the active and passive abilities.

 

[Hussar]

Yay, one of my houserules sees its way into 4e.

Seriously, didn't a lot of people do it this way before? Now it's just codified. Automatic Take 10 on Spot is a fairly common ruling.

 

[Lindorie]

As you pour yourself some OJ, you notice, out of the corner of your eye, the keys.

Absolutely perfect example. That may have happened to me, ummm, maybe once or twice.

That is called 'Male Pattern Blindness' or 'Domestic Blindness'; well so my wife tells me when I can't find something right in front of me

::chuckle:: Which is *exactly* why I relate to well to D'karr's example. We also have the "below the knee" rule. If it's below the knee, I usually don't see it.

From this, I easily see how a passive check could be more than an active. I also take from this thread that the usual use of passive rolls will be to allow the DM to check something without alerting the players.

So, if someone is on sentry duty [active checks with rolls], the movement in the corner of their eye may be what gets their attention [passive checks without rolls]. However, they, or the DM, still make active check rolls to determine what they can see (that fourth kobold sneaking up).

 

[Rex Blunder]

If you think that it's a problem that there is a 45% chance of lower active than passive perception, and houserule it so that perception rolls cannot be below 10:

Then you should houserule all 3.5 skills. In any situation where you can "take 10", say on a jump check, you should be allowed to roll the jump check, and then ignore any results below 10.

As others have said, the passive perception check is just a "take 10" on the perception skill.

 

[Ulorian - Agent of Chaos]

If you think that it's a problem that there is a 45% chance of lower active than passive perception, and houserule it so that perception rolls cannot be below 10:

Then you should houserule all 3.5 skills. In any situation where you can "take 10", say on a jump check, you should be allowed to roll the jump check, and then ignore any results below 10.

As others have said, the passive perception check is just a "take 10" on the perception skill.

I think this is a classic case of replying to a post before reading the rest of the thread.

Of course the passive perception check is a 'take 10'... that's more than obvious.

Please see post #9 for an explanation of how passive/active perception checks work in 4E (assuming that's not just a theory), and my reply in post #10. Actually, post #11 contains a clearer explanation. In any case, it sounds like the passive check effectively establishes a lower bound for the check (i.e. your minimum Perception 'roll' is a 10 - the passive check's 'take 10'). In other words, you automatically get a passive check in any situation that requires one (which the DM makes secretly). In addition to that, you have the option to make an active check if desired.

The bottom line is that under this method for making perception checks, the 45% chance of an active check being lower than a passive check is meaningless (again, see post #10).