The common wisdom, popularized by Arnold K. here and recently invoked by Josh McCroo here, goes that active abilities are superior to passive bonuses because they present players with a decision about when and where to use their abilities, which is conducive to strategy and fulfilling gameplay. Passive features lack this decision, and are further dinged by the fact that they tend to be forgettable, boring, and detached from the game world in favor of numbers and abstractions.
Of course I’m sure active feature advocates would agree that "active > passive in all cases" is too simple but statements like “talents should be active” and “never use small, passive bonuses” have a tendency to convince people, especially newcomers, that passive features are bad and active ones are better simply by nature of being active. Even worse, some may fall into the trap of thinking that any feature can be good as long as it is active, or that making a feature active is enough to make it well-designed.
Unfortunately, no amount of “rules are meant to be broken” and “these are just guidelines, really” can fix that; what this calls for is cold, ruthless polemic:
ACTIVE ABILITIES SUCK.
Just playin'.
It's true that active features can be really fun, and are often more compelling than passive features. But there are flaws active features may fall victim to, which we've probably all seen before. What follows is an attempt to articulate the biggest of these problems and what can be done to avoid them.
1. Too prescriptive
Consider the following:
Taruk the fighter was raised amongst the clans of the high steppe, and so gets a +1 bonus to attacks with bows.
vs.
Taruk the fighter was raised amongst the clans of the high steppe, and so once per combat he can make two bow attacks in one round.
The former implies a general familiarity with bows that one might expect from growing up in an archery-centric culture, whereas the latter implies the character's familiarity with the bow allows them to perform a technique.
The way I see it, the latter ability is appropriate form more tactically involved game like 4e, where combat is the primary way characters interface with the game, or for special enemies that merit an easily recognizable distinguishing quality.
But for PCs in more old-school-style games, there is a bit of dissonance when a very videogamey once-per-combat ability is meant to convey the sum total of an upbringing spent with a bow in hand. A passive bonus, while less dynamic, does a better job at conveying the sense that this character is from a specific place and thus has a specific background, distinct from those who were raised elsewhere.
One might argue that you can use flavor to better situate the latter ability: because Taruk is learned in the ways of the high steppe clans, once per combat he can clear his mind, invoke the spirit of the Great Eagle, and unleash two arrows in a single round. This does a better job at making the ability seem an extenion of the PC's background, but in practice still only communicates that background in a single discrete action. Plus, you can use flavor in just the same way for the passive bonus to make it "feel" like an active one: because Taruk is learned in the ways of the high steppe clans, his daily prayers to his ancestors grant him +1 to bow attacks as the Great Eagle guides his arrows.
Rule of thumb #1: Active features are generally better at embodying discrete talents and capabilities than they are at describing broad, general competencies.
2. Too dissociated
A bunch of people have said it before but I'll say it again: dissociated mechanics are pretty lame. Take the healing surge ability from later editions as an example: You press a figurative button and your character heals. Why? Because of some abstract immaterial quality like "fighting spirit." Why can you only do this an arbitrary amount of times per day? Because 1. the game would break if there wasn't any limit to this kind of ability and 2. it would break the verisimilitude if a character to just recovering all the time, but not if they recover only some of the time. This is the issue with dissociated mechanics; they apply unroleplayable elements to a roleplaying game. With that being said, dissociated mechanics are somewhat of a necessity in TTRPGs, some are better tolerated than others, and passive features can be dissociated as well. But active features a greater number of factors (in the form of limitations and conditions, such as how frequently a feature can be used and how long the active ability lasts) that open the door for disruptive dissociation to a greater extent than passive features.
As Justin Alexander explains in his essay linked above, dissociated mechanics can be avoided if there's a material component to the feature—a special tattoo, an intricate hand gesture, a magic item—that keeps it grounded in the game world.
Rule of thumb #2: Avoid dissociation where possible by tying the feature to something tangible.
3. Too Limiting
Pushing buttons is fun. Who doesn't like buttons? We love buttons. But to paraphrase the aphorism about hammers and nails, when all you have are buttons every problem looks like an opportunity to push a button.
"The answer is not on your character sheet" is an oft-discussed axiom in the OSR. It's a bit of an overstatement, and rational people can disagree on how useful or accurate it is as a game imperative, but the case still stands that active "button press" abilities may limit how players interact with the game in circumstances where such abilities offer too much of an easy out.
For instance: you're in a 5e game and the PCs are trying to get past a guard dog. You could try to come up with a way to distract or befriend it, but one of the characters has a +7 to their Animal Handling skill so they press the Animal Handling button and the problem is solved, no thinking necessary. Obviously a good DM would ensure the skill check is rolled only after the players describe what they do, but even if that were the case the system still encourages players to filter how they interface with the game through the features on their character sheets as opposed to the circumstances within the game world.
Rule of thumb #3: Active features benefit from having clear, specific functions and limitations to prevent them from being too easy to rely on.
4. Too many moving parts
Wizard jpg to close us out: