With the possible exception of combat-related tests, I suspect that perception-type tests are the most common skill tests in RPGs: What do the characters see and when do they see it?
Despite their ubiquity – or perhaps because of it – perception-type tests are surprisingly challenging for many GMs, and the art of their use can be surprisingly contentious, with those choosing to resolve them in one fashion often feeling that those who resolve them using different techniques are heretics who are ruining their campaigns. (No joke.)
Let’s take a moment to further refine our field of study. Perception-type tests, broadly speaking, can be broken down into two categories: Active perception tests (determining what the character notices when they are consciously making an effort to observe) and passive perception tests (determining what a character notices reactively and/or while engaged in other activities).
Of the two, active perception tests tend to pose little challenge or oddity: The player states their intention and method, and then the action is resolved. There may be some fiddling about with hidden vs. open stakes and difficulty numbers, but these tests are fundamentally resolved like most other tasks.
When it comes to passive perception tests, however, things get more complicated, primarily because such checks inherently create significant metagame knowledge (i.e., knowledge that the player possesses which their character does not): The test, after all, is being made to determine whether or not the character is aware of something. But the mere fact that the test is being made in the first place reveals to the player that there is something the character is (at least potentially) unaware of.
This is problematic because:
- Even if the check is successful, the argument can be made that the significant bifurcation of the player’s experience from the character’s experience is non-optimal.
- It deadens the sense of surprise. (A jump scare is less effective if you know it’s coming.)
- It lets players to abuse their metagame knowledge, allowing them to take actions based on the fact that the test was made.
- Even if the player attempts to avoid such abuse, the mere presence of the knowledge can complicate the decision-making process, filling it with an extra burden of doubt and self-analysis. (For example, maybe you would have been extra cautious about that door up ahead even if you weren’t aware that the GM called for a perception test as soon as you saw it… but are you sure? And even if you’re sure, what will your fellow players think of your choices?)
In order to avoid this cluster of problems created by the metagame knowledge of the passive perception test’s existence, GMs have adopted a variety of special procedures for such tests. Let’s take a moment to briefly discuss the major approaches.
THE PLAYER ROLLS
The first approach, of course, is to just resolve passive perception tests by having the player roll them.
PROS: This is usually the way that other skill tests are resolved, so you’re simply being consistent with your methodology.
CONS: The metagame knowledge we just discussed.
THE GM ROLLS
Okay, simple solution: The GM rolls the test in secret.
PROS: The player doesn’t know the test is being made, so there is no metagame knowledge being imparted.
CONS: The GM has to track the pertinent skill ratings for the PCs. This can be difficult to do accurately, particularly if the system features a lot of different perception-type skills or has lots of buffs, equipment, and/or transient character abilities that cause the perception-type skill bonuses to shift around. In many systems it can actually be impossible to do this, as the players will have optional resources or limited use abilities that could affect the outcome of the check.
And even if the GM does execute the checks without error, players tend to have a greater confidence in checks they rolled themselves. “Whaddya mean we got ambushed? Don’t I get a Spot check? Did you remember that I get a +3 versus spotting cyborgs?”
There is also an inherent time cost (one guy making five checks generally takes longer than five people each making a single test) and a potential pacing problem (players actively resolving something are engaged; players waiting for the GM to finish rolling dice behind their screen are not engaged).
VS. STATIC VALUE
Instead of rolling passive perception tests, the PCs’ passive perception is boiled down to a static score which is compared, without a randomizer, to the difficulty of the test.
PROS: This eliminates some of the problems with the GM rolling. Instead of a time cost, this method can actually result in a time savings, which also means that the pacing problems generally don’t crop up.
CONS: Many of the problems, however, remain (such as keeping track of the PCs’ skill ratings).
More importantly, in practice this method effectively turns passive perception tests into pure GM fiat: The GM will obviously quickly learn what the highest passive perception score is in their group, and when they set the target number for a passive perception test they are ultimately just deciding whether it’s higher or lower than the party’s score. There’s nothing inherently wrong with the spectrum of GM fiat, per se, but what you end up with here is this sort of fake mechanic and a bunch of extra bookkeeping which seems to have no real purpose except to camouflage the fiat. If this is the approach you want to take, it seems to me that you’d be better off skipping all the hassle and just embracing the fiat directly.
UNCERTAIN TASKS
As discussed in The Art of Rulings, you could also adopt the uncertain task method described in Traveller 2300. In this method, both the GM and player resolve the test separately, and the combination of those outcomes results in either no truth, some truth, or total truth.
PROS: The method obscures some of the metagame knowledge imparted when the player makes the roll (i.e., they can’t intuit reliably based off their knowledge of what their die roll was). The GM also doesn’t need to track the PCs’ perception scores, because they can just ask for that information as the check happens.
CONS: This resolution method is more time consuming, particularly when you’re dealing with a scenario where everyone in the group is making the passive perception test. Muddling out five different test result comparisons can be laborsome by itself, but the spectrum of potential results can also create a great deal of confusion when different characters getting different results simultaneously. (Maybe you could have everyone roll and then only resolve the uncertain task comparison check with the character who rolled best to determine what the group actually observes?)
I have always, as a GM, rolled on behalf of the players… But I very often also make some dummy rolls to prevent meta gaming, at random times throughout the session. This allows you to ask the players what their relevant stat is while freaking them out when you make a dummy roll.
I have a tab on the google sheet that I track information on that is a “perception randomizer” Given the DC, and the Players bonus it figures out how many numbers on the die are successes and then randomly assigns successes and failures to random numbers.
I also tend to have some other thing for them to notice if it is a “failure”
Then the player can still roll to use “their” luck instead of mine. I have it set to do all the players in my game so I can refresh the page, have them roll and tell me what the Die says. Not very time consuming and they never know if their 4 missed the important thing, or got it.
I use the static value most of the time (playing 5e) but, to avoid the DM fiat, I’ll roll for the difficulty of the thing being tested. (reversing the question from “how perceptive are the characters?” to “how well was it hidden?”)
This does mean I know ahead of time who is likely to find something I’ve prep’d, but it helps me avoid my own bias in how I want the scene to play out (when I want to avoid it, anyway). If *I* want to be surprised, I’ll handle the roll at the moment of encounter.
A drawback to this approach is that, all else being equal, the most perceptive character always spots anything the least perceptive character can spot. This is mitigated somewhat by the variety of ways my players have to encounter a thing; It’s rare that all characters get the opportunity to spot something at the same time.
Having recently started playing 5E for the first time I am really enjoying Passive Perception. Due to the fact that I’m running a published adventure (Tomb of Annihilation) the DCs required are created for me so there’s no element of DM fiat.
It also gives me the opportunity to prepare for what the party is likely to spot with their passive perceptions and tailor my prep more efficiently.
Rob: Your system of rolling for the difficulty of the thing being tested seems really great, especially rolling ‘at the time’ to allow for more spontaneous improv.
Of course…
http://www.giantitp.com/comics/oots0003.html
…in case anyone hasn’t seen it yet!
For the most part, I use passive perception vs an active stealth roll from the hiding enemy. Only one roll for the table and no fiat involved. They players don’t know why you are rolling so it reveals little meta data (especially if you get in the habit of faking rolls).
For active searches or players simply “keeping an eye out,” it works well if you ask the players what their Focus is. Players that say their Focus is traps, or secret doors won’t notice the cloaker above them. Players that are looking for enemies won’t notice the pit trap.
Players might Focus on environment (traps/secret doors), mapping (not getting lost), enemies (sneaking creatures), and in some games you might have Astral or Matrix-type perceptions.
I use the passive perception static value method but effectively roll for the DC value as not to rely on fiat. Then compare this against the relevant passive perception value. Either the highest in the group or whoever is most obviously about to spot the trap or ambush.
For example if I set say a pit trap as DC 10 I’ll roll d20+0 , DC 15 is +5 , DC 5 is -5 , DC 12 is +2 etc.
Opposing stealth rolls are resolved with stealth against passive perception as is normal.
I feel this marries the best of both methods, stops metagaming, avoids fiat and still only requires the one roll and knowing one passive perception score for the most part.
I use a fairly simple solution, which is that I almost completely eliminate passive perception rolls. If the player doesn’t say that he or she is examining something or otherwise staying alert, I usually only tell them the obvious stuff. And if they are being actively perceptive, I have them roll no matter what, and I don’t tell them the DC.
The only information leakage is that players are pretty certain they have seen all there is to see if they roll high, and they know that they don’t know if they are missing something when they roll low. But you can’t get completely away from metagaming.
I just periodically ask my players to “roll a die” (i.e. a d20). Sometimes it’s a perception check or save of some kind and they often figure out what it was as soon as I describe the results, other times it’s a check that’s not immediately obvious, and still other times it’s a dummy roll. A few times I’m even asking them to roll for some non-player entity. I guess in terms of your listing above this is closest to number two, but does seem to ameliorate a couple of the cons by making the rolls player-side but hidden in a sense.
I suppose if you wanted to be really involved with it, you could have the players roll every time they enter a new area or end a scene and use those as your encounter dice (or other “bookkeeping rolls”) as well, etc. etc.
Running an OSR dungeon (Stonehell) converted to 5e, I came up with a variant different from any of these:
I use the static PC ability (Passive Perception) but I roll for the task difficulty when the PCs get there. Just as the monsters roll Stealth vs the PC Passive Perception, I roll eg d20+10 for the difficulty of spotting a secret door or something that would have a static difficulty of 20; d20+5 for a 15, d20 for a 10. If PCs engage in active searching I can keep the number I rolled and they all roll against it, or I could use 10/15/20 if that looks more appropriate.
I find this works very very well in practice.
I’ve always wondered about using static values if instead of doing the GM fiat thing, you assigned a modifier to the perception check, then rolled to get a DC. For example, player X has passive perception of 15, I assign say a +6 as the difficulty of the check and roll to randomize it, let’s say I roll 12 for the example. The DC is then 18 and thus the player would fail. You can then figure out the DC ahead of time as well but limit the GM fiat problem.
Oops – read more comments and others have already mentioned this – sorry!
In Traveller for uncertain rolls I use a technique that doesn’t work in a single d20 system. The player rolls one dice openly, and the gm rolls one dice secretly. The GM knows the final score, so the pass or fail state and level of effect. The player has some idea but not the full picture. The GM just tells the player what they experience based on the actual result, the player has to decide if that experience represents a pass or fail.
For perception I use this when important, but also have “things to notice” that aren’t really important. The players can’t be sure if they missed something important or not, or succeeded with nothing important to see. I’ve been doing this in that game over 10 years now.
In my own RPG system I do this too, having the player roll a fixed number of dice and the GM secretly roll the extra dice. Works well.
I always have the players roll, then give them some form of information whether they passed or failed. Best roll was 12? There’s water dripping from stalactites on the ceiling into a rippling rocky pool ringed by pale green fungi. Best roll was 19? As above, but I also mention the 4 giant bats hiding among the stalactites.
You’ve made a basic error right at the beginning.
There’s no such thing as an active check.
A passive score is used when the player cannot know a check is being made (secret check) or when the character is actively doing something repeatedly, like keeping an eye out for threats as they travel/explore. The latter is just to prevent having to roll over and over again.
A rolled check is made when the action is being taken and resolved once, and the result doesn’t need to be kept secret from the player. Such as taking the Search action to locate a creature that just turned invisible in front of you and used the Hide action.
@Tanarii: You’ve made a basic error right at the beginning in assuming that D&D 5E is the only RPG that exists.
The good news is that you’ve got a lot of exciting adventures ahead of you!
“A rolled check is made when the *action* is being taken and resolved once” (emphasis mine)
Even if this were about 5e explicitly, I’m fairly certain “an action” is what is meant by an active check. As opposed to something you just notice. Just because he used the words “active check” doesn’t mean it has to be some technical term in the rulebook. We can use logic and intuition to figure out what is meant.
I get so tired of this “no such thing” argument in 5e. People keep claiming there is “no such thing” as a surprise round in 5e. So what, then, should I call the round in which all the surprised people don’t get to act?
Back on topic, I tend to use GM roll sometimes and player roll sometimes. This has the added benefit of making my occasional GM fiat less jarring to the players (because of gm rolling), but the main reason I do it is because sometimes I sense the action is getting bogged down by a ton of rolls and looking up of things and I just want a quick resolution to keep things moving.
I also tend to describe flavor things they notice on a failure, but I saw in the comments the idea of randomizing numbers so the players don’t know if visible rolls were successful or not. It sounds a bit complicated to me, but I might start randomly swapping the 10s place to keep them on their toes. (eg a roll of 1 = 11, 13 = 3, 10 = 20, etc)
I had some modest success in a 3.5e game with having players pre-roll their own “hidden checks”. At the beginning of the session I passed around a piece of paper, and had every player roll 20d20 and write down their results. I then took the sheet and rolled a d20 (behind the screen) for each player to determine where I would start in their sequence. This seemed to be enough to throw off any sequence memorizing. As we went through the session, I would cross off a number every time they made a hidden roll (Spot, Listen, Will Save etc…). On the plus side, it allowed me to make hidden rolls for the players without tipping them off, and it also seemed to give the players a sense of ownership because I was still using “their” rolls. On the minus side it ate up a bit of time at the beginning of the session.