I look at RPGs from a lot of different angles on this blog. Today, I'll look at them from the easiest angle of all: What you actually do.
The Main Action of an RPG is what the players spend most of their time doing in it.
For the purposes of today's post, I'm going to exclude out-of-character time and in-character planning time from the main action of an RPG. I have three reasons for excluding planning time. First, some groups love planning, and others prefer to jump right into the action. Second, planning time doesn't involve the game system very much, and an analysis of main action is most valuable to system designers and players creating characters. Third, planning time is often time spent Securing Strategic Advantages (below) - not actually planning, but gathering resources to make the plan (if any) easier.
Below, I'm going to describe some of the most common things players spend their time doing in tabletop RPGs. It seems simple, even obvious, but thinking about your game in terms of main action will help you produce a tighter, more focused experience.
Common Main Action Types in RPGs
Thanks to the war-game legacy of D&D and the violent nature of science fiction stories, tabletop RPGs tend to have a lot of combat. Even games like Trail of Cthulhu or Vampire: the Requiem tend to have a lot of combat, despite being "about" other things. Combat may not be the #1 most common activity in every RPG, but it's probably going to be in the top 5 for almost every RPG.
Exploration in tabletop RPGs is best defined as "cautiously looking for things in dangerous territory." Maybe the PCs are looking for a way out of the underdark, looking for clues about a serial killer, looking for a powerful magic staff, hunting for a spy, or looking for a hidden treasure room.
Just like novelists tend to skip salutations, rote dialog with faceless extras, and polite small talk, players and GMs often hand-wave these non-dramatic social moments. Instead, the main action of social scenes focuses on lying, interrogating, interviewing, learning, persuading, bullying, pleading, negotiating, and evading. Social scenes can be challenges when the PCs are talking to enemies as well as allies - in fact, they tend to be more fun with allies.
Sneaking past live opposition is very common in RPGs. It's a go-to stakes-raising scene for GMs because most PC parties have several characters who are bad at it. It's also good for tension because the goal is to avoid being caught by someone dangerous. There are other kinds of sneaking: In D&D and Pathfinder, for instance, the Rogue usually scouts ahead for the party. In modern police or spy games, the PCs are often placing NPCs under surveillance. See below for more on sneaky investigations.
Physical challenges are all the tough, hazardous things PCs do, like parachute into enemy territory, climb a mountainside to get to a ruin, carefully avoid a trap, escape a forest fire, survive in the desert, or swim to safety from a shipwreck.
Securing Tactical Advantages
A tactical advantage is something that improves the party's position against a nearby, immediate enemy. This includes setting an ambush, separating foes before combat, gaining leverage over social opponents, distracting enemies the PCs plan to sneak past, and so forth. When you slow the pace and open a scene on an opportunity or frame a scene farther back from the action, the players tend to spend at least half the scene securing tactical advantages, before engaging the action.
Securing Strategic Advantages
The rising action of a story involves getting resources, recruiting allies, and learning about the enemy. These are all strategic advantages. Just like most of an adventure novel takes place during the rising action, most of the action of a tabletop RPG relates to the rising action. A lot of the rising action in tabletop RPGs falls into the categories above (social scenes to recruit allies; combat scenes to defeat the enemy's lieutenants; exploration scenes to find clues about the nature of the enemy); but some of it is pure advantage-securing. In Pathfinder, the players spend a lot of time shopping and crafting magic items, recruiting and managing henchmen, building strongholds, and so forth.
A puzzle solving scene happens when the players have to use their real-world brain power to solve a puzzle or mystery that can't be solved with dice. Sometimes game mechanics and dice can help by providing hints or even letting the players declare facts, but by and large, puzzle solving is a staple of tabletop RPGs. Not every session has a puzzle, but often "figuring out what's going on" is a puzzle. The PCs will frequently spend some time going over the clues they have and putting them together. This is a kind of puzzle solving.
The Honorable Mention Section
As discussed above, the time players spend planning often falls into securing strategic advantages and puzzle solving. It often looks like this: The players will spend time talking to each other trying to figure out what's going on (puzzle solving), then the PCs will go talk to an informant (a scene that mixes securing a strategic advantage and a social challenge), then they'll try to get a piece of specialized equipment (pure securing strategic advantage), then they'll search for a back entrance to a key location (securing a strategic advantage and exploration), and then they'll beat up some guards to get their uniforms (combat to secure a strategic advantage).
But often a group will take 15 minutes to talk about what they should do next and how they should make it happen, after they've already figured out what's going on. A good GM provides the PCs with multiple leads to follow, and it's a sign that they're all interesting if the players have to take a break to argue about which way to go next. A good GM leaves it open how to defeat the antagonist, and it's a good sign that it's not railroading if the players are all arguing about how to do it.
Investigation is an activity that encompasses social challenges, securing strategic advantages, exploration, and sneaking. Because of the diverse methods of investigation, I consider it a type of adventure more than a type of main action.
Sneaking is listed, above, but a specific kind of sneaking deserves mention: Investigative sneaking is the sort of stealth challenge where you're investigating active opposition while trying to avoid being noticed doing so. Examples include shadowing, surveillance, stake-outs, scouting, hacking, planting bugs, and talking to informants without tipping the enemy to the leak.
Another type of action that could be a "main action" type is the elaborate con. In Reavers of the Harkenwold (an excellent adventure for 4e D&D that gives the players a lot of meaningful choices), the PCs can choose to disguise themselves to get into an enemy fortress. Such a scene comes with a lot of securing tactical advantages, social challenges, and sneaking.
A specific type of Physical Challenge is the chase scene. Many RPGs have specific mechanics for chases. D&D and Pathfinder, strangely, don't have good ones. Here's my 5e D&D suggestion. Chase scenes mix combat and physical challenges, and may qualify for their own entry as a category of main action in some RPGs, but they're not as common as they should be.
Once the Thief was introduced in the Greyhawk supplement to original D&D, picking locks became a thing RPG parties had to do more of. Later games preserved and even elaborated on that activity. Cyberpunk introduced elaborate security systems for PCs to bypass. Even within the gothic punk aesthetic of Vampire: the Masquerade, there's a Security skill for picking locks and bypassing alarms. Even in the narrative-focused Fate Core, there's a Burglary skill. But bypassing security systems, even when it's an important part of the story, hardly takes much time; and because it's almost always just a skill check, it would be boring if a GM made it take more than ten or fifteen minutes of game time, tops.
Using Main Action
I may have made it look like there are some kinds of action that dominate every tabletop RPG, but that's not really true. A Dramasystem or Microscope game, or just a highly political Fading Suns game might not have any combat at all. Some RPGs simplify securing strategic advantages, allowing players to retroactively give themselves strategic advantages, such as Leverage: the Roleplaying Game and Night's Black Agents; so players can downplay those activities to some degree. Other games minimize mystery and focus more on hack and slash. Some even give you a die roll to solve mysteries. A four-color Champions game might have literally no puzzle solving.
Further, even within some RPGs, the main action can be dramatically different. Sure, a Pathfinder game is likely to have a lot of combat and exploration, but will it have a lot of social challenges? Or almost none? As a GM, you can communicate something about the main action of your adventure or campaign in your pitch to the players. If you bill your Pathfinder game as a political thriller with a lot of mystery and intrigue, the players know you're downplaying standard dungeon exploration in favor of puzzle solving and social challenges. There will probably still be combat and exploration, but player characters will need better Charisma skills. As a player, you can build your character to be fun to play in that sort of action. It's Pathfinder, so you're going to need a sword, of course; but now you know to make sure your Fighter puts some ranks in Intimidate, and you have to try to write a background with more hooks into the politics of the setting.
As a game designer, you can construct your system to focus on the main action of the types of games you want it to be used for. If your game is about sword-and-sorcery dungeon crawling, do you really need 25,000 words on magic item creation, like Pathfinder? Or should you relegate it to just a few pages, like 5e D&D? Or cut it to one sentence, as in Dungeon World? (For reference: "Players can make magic items through the wizard’s ritual and similar moves.")
So main action has implications for everyone, from designers to GMs to players. It's worth thinking about the main action in your game.