Monthly Archives: May 2017

Ability Checks—From the Worst Mechanic in Role-Playing Game History to a Foundation Of D&D

Dungeons & Dragons makes ability checks a key part of play, but these checks took years to enter the game. How did ability checks advance from house rule, to optional rule, to a foundation of fifth-edition D&D?

Before D&D added ability checks, players found a style that mostly avoided a need for such rolls. See A Lack of Ability Checks Shaped How People Originally Played Dungeons & Dragons. Even so, characters tried things that the rules didn’t cover. For many of these actions, success or failure hinged on a character’s ability scores. Gary Gygax told dungeon masters to guess the odds of success and roll for it. But DMs and players wanted more consistency and less guessing.

In 1976, issue 1 of The Dragon printed “How to Use Non-Prime-Requisite Character Attributes” by Wesley D. Ives. The article proposes a sort of ability check before anyone coined a name for it.

This first ability check suffers from a mechanic so baroque that it reads like a gag.

To determine an action’s success, perform these actions:

  1. Roll d100, add the ability score, and then use this result to determine which die to roll in step 2. On a result of 1-20 roll a d4; on 21-40 roll d6; on 41-60 roll d8; 61-80: d10; 81-100: d12. To cope with results higher than 100, create a house rule for this house rule.
  2. Roll the die determined in step 1 and multiply the number by the attribute. This result becomes the chance of success.
  3. Roll a d100. If the result is less than or equal to the probability from step 2, you succeed!

The method requires three rolls, multiplication of double-digit numbers, and a table. But if that seems too simple, the article offers optional rules accounting for character level and class. All this yields an outcome barely more realistic than a coin flip.

To settle on an ability-check mechanic that required so much fuss, the author must have seen checks as a rare undertaking.

Despite the tortured mechanic, the idea of ability check marks a major innovation. None of the few role-playing games available in 1976 featured anything like the concept. In a few years, every RPG would build on the idea.

In the Advanced Dungeons & Dragons Player’s Handbook (1978), Gary invented a playable ability check for the Dig spell. “Any creature at the edge (1’) of such a pit uses its dexterity score as a saving throw to avoid falling into the hole, with a score equal to or less than the dexterity meaning that a fall was avoided.

By the late 70s, the method found in the Dig spell turned into common house rule: To make an ability check, players tried to roll under an attribute on a d20.

The 1980 D&D basic rules by Tom Moldvay made this house rule official. “The DM may want to base a character’s chance of doing something on his or her ability scores (Strength, Dexterity, and so forth). To perform a difficult task (such as climbing a rope or thinking of a forgotten clue), the player should roll the ability score or less on 1d20. The DM may give a bonus or penalty to the roll depending on the difficulty of the action.

Meanwhile, other role playing games advanced the state of the art. Traveller (1977) introduced skills and a single mechanic for skill checks. Runequest (1978) boasted skills and “attribute rolls” that multiplied an ability by 5 to set a percentage chance of success.

In games with skills, the skills cover most tasks a player might attempt, so ability checks blur into skill checks. Fifth edition intentionally makes skills an addition to ability checks.

For AD&D, Gygax showed little interest in ability checks. Improvised rulings worked fine for him. (When the DM is E. Gary Gygax, no player quibbles with a ruling.)

As for skills, Gygax preferred to keep D&D’s class archetypes pure. His Unearthed Arcana (1985) added weapon proficiencies as a sort of weapon skill, but the narrow scope kept the sharp lines between classes. Oriental Adventures (1985) extended the concept to create non-weapon proficienciesskills without the name. These new proficiencies never overlapped with class abilities.

After Gary left TSR in 1985, his successors on the AD&D team lacked the clout to make sweeping changes to the company’s flagship game. Nonetheless, their additions inched AD&D closer to matching the ability checks and skills in other role-playing games.

Ability checks finally reached AD&D in the Dungeoneer’s Survival Guide (1986). Although this book’s title suggests a focus on player strategy, this guide brought key rules innovations to AD&D. Here, the non-weapon proficiencies from Oriental Adventures became options in the primary game. When players used non-weapon proficiencies, they made proficiency checks to determine the outcome. These checks operated like ability checks, but proficiency improved the chance of success.

The new system of featured all the ingredients of a modern skill system, but suffered a few drawbacks:

  • Class abilities already covered most of a character’s actions, so non-weapon proficiencies rarely came up in play.
  • The phrase “non-weapon proficiency” proved unwieldy. The term evolved from Gary’s own work on D&D, but it forced a lot of extra syllables on players just to avoid contaminating D&D with anything called skills.
  • Roll-under ability checks confused players and designers.

For D&D’s other d20 rolls, players aimed high, but for ability checks they aimed low. This simple difference fostered confusion. The original ability-check rule said, “The DM may give a bonus or penalty to the roll depending on the difficulty of the action.” That meant a bonus subtracted from the roll—an ugly break from intuition.

A cleaner method adds the bonus to the attribute, so players roll under a higher number.

By now, some Internet critics might scoff at my notion that adding roll-under checks to D&D confused people. I imagine an argument heaping contempt on idiots who clearly lack the intellectual capacity for RPGs. Go back to Candyland. Who would let roll-under checks trip them up?

The D&D team at TSR.

Sometime during playtesting, the Dungeoneer’s Survival Guide apparently switched its method of applying modifiers, but the book reached print with an incomplete change. The “Sage Advice” column in Dragon issue 118 tried to sort out the mess. “OK, OK, OK, already! You’re right—there is something wrong with the DSG non-weapon proficiency system.

We went through the manuscript and thought we had caught all the places where the text needed to be changed. We missed a couple of simple ones, and this caused a tremendous problem in the system.

TSR management insisted that second edition AD&D remain broadly compatible with the original. The Player’s Handbook (1989) included a corrected version of non-weapon proficiencies as an optional rule. Ability checks entered the core game, but languished in the glossary.

For D&D’s third edition in 2000, the designers finally gained leeway to correct old drawbacks. Ability checks flipped so players aimed for high rolls. Skills embraced the actions characters actually did in the game. And no one had to say or type “non-weapon proficiency” ever again (unless they tell this story).

A Lack of Ability Checks Shaped How People Originally Played Dungeons & Dragons

Dungeons & Dragons includes three types of d20 rolls: saving throws, attack rolls, and ability checks. Saves and attacks come from the original game, but ability checks first got a name 12 years later. Ability checks began as an obscure rule where players tried to roll low on a d20. In second edition, the rule for ability checks only appears as one paragraph in the glossary. Today’s style of check finally arrived in 2000.

Modern D&D players make ability checks throughout the game, so a D&D game without checks seems stunted. But before ability checks, D&D players found a style that mostly avoided a need for such rolls.

In A Quick Primer for Old School Gaming, Matthew J. Finch describes this original style. “The players can describe any action, without needing to look at a character sheet to see if they ‘can’ do it. The referee, in turn, uses common sense to decide what happens.

You don’t have a ‘spot’ check to let you notice hidden traps and levers, you don’t have a ‘bluff’ check to let you automatically fool a suspicious city guardsman, and you don’t have a ‘sense motive’ check to tell you when someone’s lying to your character. You have to tell the referee where you’re looking for traps and what buttons you’re pushing. You have to tell the referee whatever tall tale you’re trying to get the city guardsman to believe. You have to decide for yourself if someone’s lying to your character or telling the truth.

To players who still favor D&D’s early versions, the lack of ability checks counts as a feature. Faced with an challenge, players must observe and interact with the game world. Instead of scanning their character sheet for solutions, players rely on their wits and ingenuity. Without checks, the game tests player skill more than character stats.

The absence of checks encouraged dungeon masters to assume that characters brought enough competence to succeed at ordinary tasks. For example, if characters wanted to bind a prisoner, they tied him up. But in third edition, characters relied on Use Rope skill, which often painted heroes as ridiculously inept at knots. I once played a convention game where a DM stretched Use Rope failures into hours of tiresome gaming. DMs can always skip a check for a simple task, but the presence of a skill tended to encourage checks.

Early characters could tie knots and they found pits by tapping on the floor with a 10-foot pole, but they still attempted actions that defied common-sense resolutions.

In the original game, common tests of an ability each brought a separate rule. To see if characters perceived a secret door, the dungeon master rolled a d6. Typical feats of strength relied on two different mechanics: Bending bars and lifting gates required a percentage roll, but bashing doors required a d6 roll.

If a situation came less frequently, the game offered no rules. So how could a dungeon master decide whether a character crossed a tight rope?

In the Advanced Dungeons & Dragons Dungeon Master’s Guide, Gary Gygax describes his approach. “Allow the dice to control the situation. This can be done by assigning reasonable probability to an event and then letting the player dice to see if he or he can make that percentage.” Gygax made up rulings on the spot to suit whatever seemed “correct and logical.”

This approach led to the jumble of the original D&D rules. Faced with a game situation, Gygax tended to invent a roll that settled the outcome. If the situation came up enough, the method become a rule.

Many dungeon masters felt uncomfortable embracing Gary’s improvisation. D&D players frequently try things that test a characters’ ability scores, and DMs wanted a fair and easy way to decide the outcome. Their players wanted consistency too. Rules become the laws of physics in the game world. If a rule exists for an action, players understand how it’s resolved and their chance of success. Players enjoy that transparency.

The first ability check mechanic reached print in 1976, but ability checks would take decades to become a foundation of D&D.

Next: Ability checks—from the worst design in role-playing game history to a foundation of D&D.

Running Scenes and Summaries that Invite Choices and Reveal Characters

My last post explained how scenes and summaries allow game masters to speed past uneventful time in the game world and focus on the action. This post offers more advice on running scenes and doing summaries.

Running a scene

Before starting a scene, you need two essential ingredients: (1) characters with a goal and (2) an obstacle that stands in their way.

To start a scene, set the scene. Describe the time and place. Make the description vivid. Finish your description with the thing that will spur the players to action. In a classic Dungeons & Dragons game, the call to action comes from the monster in the room. Mention the monster last, because otherwise your players will plan their attack and ignore your description of the bas-relief, the incense, and the patter of dipping liquid.

A monster will launch some scenes into motion, but other triggers could be the duchess asking why the characters intruded on her battle council, birds crowding the rooftops to silently watch the players, or anything that invites players to act. A good call to action hardly needs the usual follow up question: “What do you want to do?” Nonetheless, characters might ignore the call. The party might see the gathering flocks as a threat, or the druid might want to have words, or perhaps they count the birds as an omen and move on.

The rules of most role-playing games dwell on the scenes, leaving little need for more explanation.

How to do a summary

A summary skips the uneventful parts of passing game time. It begins when the scene ends—when players look at the scene’s outcome and decide what to do next. Often, they choose a goal that carries them to their next scene.

During a scene, the players’ choices tend to focus on overcoming an immediate obstacle. But during a summary, the players’ choices tend to drive the adventure. If players pass too many summaries without a choice to make, your game may start feeling like a railroad.

In a summary, damage is healed, resources replenished, and so on. Players can describe as much of the activity as the game master.

“We go to the docks and find the captain of the Salt Mist, and then hire her to sail north to the City of Sails. Does anything happen along the way?”

“No. After 3 days at sea, you dock in Luskan on the Open Shore.”

If the passage of time presents new developments that might change the players’ plans, then mention the events and give players a chance to interrupt the tale and make new choices. Perhaps something happens on route. “On your second day at sea, you spot a thick column of smoke rising from inland, just beyond a hill.”

You might remind the players what makes their new options interesting. “As you talk about investigating, the captain seems too willing to put you ashore, and you suspect she may be eager to leave you behind.”

When a summary takes players someplace new, add enough description to give the flavor of the experience, and a sense of the passing time.

A summary can include colorful moments that inspire players to act in character. For example, if the party spots a live stag with an arrow in its flank, does the druid heal the beast, or does the ranger finish it and host a feast? Such moments usually lack the ingredients of a scene, but they offer hooks that let players reveal their characters.

Accelerating the pace

When a summary covers familiar ground, shorten the narrative. That first journey to the City of Splendors deserves some color. The third can pass in a sentence.

As players approach their ultimate goal and the climax of the adventure, they will lose patience for long summaries. When adventurers first reach Barovia, players may enjoy stately trips from town to town. But when the party stands ready to confront Strahd, cut directly to the gates of Ravenloft.

A cut eliminates all the narrative between scenes. The players might say, “We want to question the longshoreman to see if anyone saw the Salt Mist.”

“Okay, now you’re in the Siren’s Call as the place fills with thirsty roughnecks.”

Cuts rush past the flavor of the game world, and short circuit the players’ chances to make choices. Early in a campaign, avoid cutting between scenes.

Near the end of a long campaign, cuts grow more welcome. When few choices remain and when players feel eager for the story to reach a climax, cuts accelerate the pace.

Letting players take the narrative

In How to Say Yes Without Turning Your D&D Game Into a Joke, I talked about how the GM bears responsibility for the game’s challenge. Often, a GM must control the narrative so players face meaningful obstacles. But in a summary, no obstacles block the characters’ progress. This makes a summary the ideal time to let players tell their characters’ tales. For example, if the players spend 10 days waiting on town, ask each player for their character’s story of the downtime.

At the end of the adventure, when the characters return to the town they saved, let them tell of their hero’s welcome. Who celebrated with the fetching Sheriff? Or maybe keep that to yourself. This is a family table.

During a summary, when players take the narrative, characters gain chances to reveal their personalities. Plus, you get a break while they do the talking. That’s how you win at Dungeons & Dragons.

How to Use Scenes and Summaries to Focus on the Best Parts of a Role-Playing Adventure

This started as a post on pacing until I checked other game masters’ advice on pacing and discovered that nobody discussed the same topic. Some “pacing” advice helps GMs run at a brisk tempo. For that, see my posts on initiative, delegation, and how to end a battle. Some explained story beats, dramatic tension, and the three act structure. I’m not clever enough to finesse such narratives without my players noticing a loss of freedom.

So this post covers scenes and summaries.

Have you seen the image that explains Dungeons & Dragons as the game where a 3-hour walk takes 5 minutes, but a 5-minute battle takes 3 hours? That sentence tells the difference between scene and summary.

Game mastering advice rarely talks about scene and summary because game masters tend to manage the two by feel. Mostly, feel works okay, but often not. Although scenes feature the game’s excitement, dull role-playing sessions start when a GM tries to make a scene from time that should pass in summary. On the other hand, a bad summary makes player feel rushed and railroaded.


In a role-playing game, scenes focus attention on the times when players fight a battle, talk to an non-player character, or search a chest for secret compartments. In a role-playing game session, scenes show all the action. During scenes, players make every decision for their characters. In combat scenes, game time expands so players can focus on small decisions and use the game rules to determine outcomes.


A summary skips the uneventful parts of passing game time. Summary speeds past the times when players travel a safe road, search a library, or collect a reward from a patron.

A good summary leaves players with a sense of passing events and with chances to pause and make decisions. During a summary, characters heal damage, tally and replenish resources, weigh their options, and make the choices that lead to the next scene.

When to run a scene

To start, a scene needs two ingredients: characters with a goal and an obstacle that stands in their way.


The classic D&D scene starts with the goal of treasure and the obstacle of a dragon. Sometimes, monsters attack and the party goal becomes to survive. (In those cases, especially, think about the monsters’ goal. See Create better encounters by considering what your monsters want.) The most interesting encounters often feature a goal different from kill all the monsters.

A goal needs enough stakes to merit a scene. If the party goes to the fletcher for arrows, the chance to save a few silver hardly calls for a negotiation scene.

Typically, role-playing scenes combine a goal of gaining help or information, with the obstacle of an uncooperative non-player character.

When characters lack a goal and a GM launches a role-playing scene anyway, players wind up wondering they are supposed to do. See A priest, a warlock, and a dwarf walk into a bar and…nothing happens.


The obstacle in a role playing scene comes from any NPC reluctant to help anyone who asks. For help creating the obstacles needed for compelling role-playing scenes, see 22 Reasons why a non-player character won’t cooperate.

A true obstacle must bring a chance of failure. If players face a locked wooden door, but they have unlimited time and an axe, the door fails as an obstacle. On the other hand, if the crash of an axe into boards could bring monsters, players face a dilemma and the scene has an obstacle.


When players explore, they have a goal—perhaps only find the treasure—but they may face unknown obstacles. The unseen hazards make the players’ choices important and make the exploration work as a scene. If a scene continues for too long with unknown obstacles, players may lose interest. Add a reminder of nearby peril. Perhaps strange sounds echo through the stones, or a chill passes the corridor.

In exploration, when no obstacles lurk nearby, the game master can rely on summary. “You look through all the rooms in the cellar and find a polished, black ring among the rubbish.”


Sometimes game masters start a role-playing scene without a goal or obstacle because they want exposition. At the start of an adventure, players tolerate such scenes. The implied goal becomes, learn our goal. Scenarios often add a minor obstacle by introducing a patron who needs the right questions to provide extra help and information. However, such weak scenes typically work better in summary.

I used to make the mistake of trying to conclude adventures with a scene where characters meet their patron to collect payment and tie any loose ends. I learned that as a scene, denouements never hold attention. While players tally their loot, just summarize the medal ceremony.

Exception: Scenes that work as a reward

When a game master announces treasure, players tend to pay careful attention to their reward. Likewise, role-playing scenes that reward players with information can hold attention even when the scene lacks an obstacle. These scenes feature players with questions and a colorful NPC ready with answers. Crucially, these scenes still feature a goal. Players must want the information enough to have fought for it and won. Don’t dump unwanted backstory and call it a scene. See How to reveal backstory in a role-playing game session.

When to do a summary

Whenever an game session lacks the ingredients for a scene, a goal and an obstacle, you can rely on summary. If you feel unsure about switching to a summary, ask the players. “Do you want to do anything special, or should we move forward?”

During a summary, as game time speeds along, players can feel like they lose some control over their character. Among other things, my next post will explain how to do a summary without making players feel like passengers on a railroad.

Next: Running Scenes and Summaries that Invite Choices and Reveal Characters

How N1 Against the Cult of the Reptile God Changed D&D Adventures For Good

When Dungeon issue 116 ranked the 30 greatest Dungeons & Dragons adventures, N1 Against the Cult of the Reptile God landed at number 19. Ed Greenwood summed the 1982 adventure as, “Detective work, hunting for villains, some monster-bashing, and a settlement detailed enough to use beyond the scripted adventure; a quiet little gem that has it all!”

The adventure’s creation began when Kevin Hendrix wrote an encounter with a reptile cult to serve as an episode in Len Lakofka’s adventure L1 The Secrets of Bone Hill (1981). Lakofka chose not to include the cult, so Hendrix began expanding the idea into a full adventure. In 1981, TSR layoffs claimed Hendrix’s job. The core concept and title reached Douglas Niles for completion. When the module saw print, TSR management felt wary of helping designers gain the clout of name recognition, so Hendrix, now an employee of Metagaming Concepts, received no author byline.

Tracy Hickman and his Dragonlance adventures get credit (and sometimes blame) for moving D&D from aimless dungeon crawls to a story focus. But N1 came first, and it includes a stronger narrative than any of TSRs’ earlier adventures. Niles explained, “I liked settings that allowed the characters to play out a story.” N1 features a story with rising tension and a climactic showdown, but the plot still turns on the players’ choices.

A 1983 review in Imagine issue 3 praised Against the Cult of the Reptile God and touted its “innovative touches.” What made N1 innovative?

Early town adventures tended to stumble

The original Dungeons & Dragons rules say that if a referee makes a map of a town close to the dungeons, “players can have adventures roaming around the bazaars, inns, taverns, shops, temples, and so on.” Because imaginary revelry offers scant fun, roaming town typically focused on shopping and gathering “rumors, information, and legends,” which “lead players into some form of activity or warn them of a coming event.”

Actual town adventures tended to stumble. Typically, the party visits the market and someone tries to haggle: Best case, one player saves a few coppers while everyone gets bored—even the shopper. Later, the players gripe about the tiresome D&D session when the dungeon master stubbornly limited players to shopping.

That’s the best case. Usually, a restless thief picks someone’s pockets, leading to party strife or to a confrontation with the city guard. Such trouble drove D&D designers to rename thieves to rogues. See Why second-edition Dungeons & Dragons dropped thieves and assassins.

In the worst case, the players realize the townsfolk have no chance against a band of experienced killers, leading to murder and looting. See Two weird D&D questions no one asks anymore, answered by the City State of the Invincible Overlord.

The gulf between towns and the sites of adventure

When Gary Gygax wrote T1 Village of Hommlet (1979), he prepared for the worst case. Gygax lists the treasure found in shops and homes, and then discourages looting by inventing a social network able to punish murder hobos.

Gary populated Hommlet with colorful characters who might foster role playing, but I suspect most groups paid them little notice. The real action lay in the Moathouse, because for most players, the heart of D&D lies in crushing evil and winning treasure, not necessarily in that order. In town, evil keeps hidden and gold belongs to a rightful owner.

Unless some goal drives players to talk to villagers, most players have nothing to discuss. In D&D, as in fiction, the really interesting action happens when the characters have both an objective and an obstacle that stands in their way. See A priest, a warlock, and a dwarf walk into a bar and…nothing happens.

After Gygax, other D&D authors tried to connect towns to adventure. L1 The Secrets of Bone Hill provided another home base. U1 Sinister Secret of Saltmarsh suggests that some villagers might be involved with the sinister events at a haunted house, but leaves creating the town as homework for the DM. When I played U1, the DM dropped us at the door to the haunted house and Saltmarsh remained unseen.

N1 entwined a town into the adventure

In Against the Cult of the Reptile God, the characters investigate disappearances in the village of Orlane. Fear and suspicion grips much of the town, while other folk behave oddly. Players need to interact with townsfolk to solve the mystery. A wrong move in town could bring peril.

To modern players, the setup may seem conventional, but N1 became the first D&D scenario to feature an investigation and to bring adventure into town. Before Against the Cult of the Reptile God, a gulf separated towns from the wilderness and dungeons that offered adventure. Until N1 bridged that gap, players found little reason to interact with townsfolk.

Lesson: To capture players interest in role-playing, pair colorful NPCs with a goal that invites interaction.

N1 introduced the event-based adventure

Before N1, every published D&D adventure was site based. The choices that drove these adventures all amounted to a choice of doors or of adjacent hexes. See Why Dungeons & Dragons (and Role Playing) Took Years to Leave the Dungeon.

N1 introduced an event-based scenario where active NPCs affect the course of adventure. The 1983 review spotted the change. “A noteworthy feature is that the unknown adversaries do not tamely wait for the players to come and get them. They are active.” In Orlane, the kidnappings continue as time passes. Party members can even be abducted and compelled to spy for the cult.

This advance marked another milestone. Before Against the Cult of the Reptile God, when players weren’t watching, non-player characters only did one thing: They refilled dungeon rooms emptied by adventurers. In N1, even if the players do nothing, things still happen.

As in one of pulp fantasies that inspired D&D, the sinister events in Orlane lead to a rising sense of peril. Tension increased toward a climax.

Lesson: To make the villains come alive, let them act offstage, and then show their actions in the game world.

Making the most of N1 today

Early D&D adventures like Against the Cult of the Reptile God can still work with today’s rules. Just replace the printed monster stats with numbers from the fifth-edition Monster Manual.

Against the Cult of the Reptile God plays best when the its tension builds over days of game time. To get a sense of passing days, characters need to keep busy. If they focus on rooting out the cult, they tend to solve the mystery before pressure rises. To work best, develop the events of N1 alongside a second adventure that can dominate the characters’ attention. For example, while the PCs make a few forays to the Caves of Chaos, let the disappearances and weirdness in Orlane reach a boiling point. The Encounters-program adventure Against the Cult of Chaos (2013) took exactly this approach by combining elements of N1 with T1 Village of Hommlet and B2 Keep on the Borderlands (1981).

Some critics fault N1 for requiring a 1st-through-3rd-level party to ally with a 7th-level wizard for the final showdown with the cult’s “reptile god.” The wizard overshadows the PCs, but without the ally, the party may die to a single fireball. The adventure itself suggests a solution: Have the wizard give the party a scroll of Globe of Invulnerability for protection during the showdown. Make the elderly wizard too frail to venture into the swamp, but let his familiar guide the party. For more on the risks and benefits of allies, see The Surprising Benefits of Giving and Adventuring Party a Guide.

Among the greatest adventures

Based on quality, N1 merits the standing, but based on achievements, I might rate it higher. N1 set two milestones for published D&D adventures. Thirty-five years later, it still offers lessons to dungeon masters.