D&D departs from traditional wargaming and assigns each player a specific character to play instead of a military formation. These characters embark upon imaginary adventures within a fantasy setting. A Dungeon Master serves as the game's referee and storyteller, while maintaining the setting in which the adventures occur and playing the role of the inhabitants. The characters form a party that interacts with the setting's inhabitants (and each other). Together they solve dilemmas, engage in battles and gather treasure and knowledge.^[4] In the process the characters earn experience points to become increasingly powerful over a series of sessions.

The early success of Dungeons & Dragons led to a proliferation of similar game systems. Despite this competition, D&D remains the market leader in the role-playing game industry.^[5] In 1977, the game was split into two branches: the relatively rules-light game system of Dungeons & Dragons and the more structured, rules-heavy game system of Advanced Dungeons & Dragons (abbreviated as AD&D or ADnD).^[1][2][6] AD&D 2nd Edition was published in 1989. In 2000, the original line of the game was discontinued and the AD&D version was renamed Dungeons & Dragons with the release of its 3rd edition with a new system. These rules formed the basis of the d20 System which is available under the Open Game License (OGL) for use by other publishers. Dungeons & Dragons version 3.5 was released in June 2003, with a (non-OGL) 4th edition in June 2008.^[7][8] A 5th edition was released during the second half of 2014.^[9]

As of 2004, Dungeons & Dragons remained the best-known^[10] and best-selling^[11] role-playing game, with an estimated 20 million people having played the game and more than US$1 billion in book and equipment sales.^[12] The game has been supplemented by many pre-made adventures as well as commercial campaign settings suitable for use by regular gaming groups. Dungeons & Dragons is known beyond the game for other D&D-branded products, references in popular culture, and some of the controversies that have surrounded it, particularly a moral panic in the 1980s falsely linking it to Satanism and suicide.^[13] The game has won multiple awards and has been translated into many languages beyond the original English.
- Taken from (https://en.wikipedia.org/wiki/Dungeons_%26_Dragons)

The core of D&D is storytelling. You and your friends tell a story together, guiding your heroes through quests for treasure, battles with deadly foes, daring rescues, courtly intrigue, and much more. You can also explore the world of Dungeons & Dragons through any of the novels written by its fantasy authors, as well as engaging board games and immersive video games. All of these stories are part of D&D.

The first Dungeons & Dragons game was played back when Gary Gygax and Dave Arneson chose to personalize the massive battles of their fantasy wargames with the exploits of individual heroes. This inspiration became the first fantasy roleplaying game, in which players are characters in an ongoing fantasy story. This new kind of game has become immensely popular over the years, and D&D has grown to include many new ways to vividly experience worlds of heroic fantasy.

The core of D&D is storytelling. You and your friends tell a story together, guiding your heroes through quests for treasure, battles with deadly foes, daring rescues, courtly intrigue, and much more. You can also explore the world of Dungeons & Dragons through any of the novels written by its fantasy authors, as well as engaging board games and immersive video games. All of these stories are part of D&D.

Dungeons & Dragons influenced so many games that followed in different media and genres, but it has remained a vital product in its own right, appearing in diverse editions, media, and languages, as well as spinning off into literature, film, television, and the Internet. It has been a source of inspiration for artists of many kinds, but more importantly it has enriched the lives of tens of millions around the globe, offering a chance for anyone to experience fantastic roles and situations very different from everyday life. On the occasion of the 40th anniversary of Dungeons & Dragons, and the release of an eagerly-awaited new edition, this timeline shows some important dates in the development, elaboration, and the triumph of Dungeons & Dragons.

Dungeon Master (DM): After passing through the craggy peaks, the road takes a sudden turn to the east and Castle Ravenloft towers before you. Crumbling towers of stone keep a silent watch over the approach. They look like abandoned guardhouses. Beyond these, a wide chasm gapes, disappearing into the deep fog below. A lowered drawbridge spans the chasm, leading to an arched entrance to the castle courtyard. The chains of the drawbridge creak in the wind, their rust-eaten iron straining with the weight. From atop the high strong walls, stone gargoyles stare at you from hollow sockets and grin hideously. A rotting wooden portcullis, green with growth, hangs in the entry tunnel. Beyond this, the main doors of Castle Ravenloft stand open, a rich warm light spilling into the courtyard.

Phillip (playing Gareth): I want to look at the gargoyles. I have a feeling they’re not just statues.

Amy (playing Riva): The drawbridge looks precarious? I want to see how sturdy it is. Do I think we can cross it, or is it going to collapse under our weight?

Unlike a game of make-believe, D&D gives structure to the stories, a way of determining the consequences of the adventurers’ action. Players roll dice to resolve whether their attacks hit or miss or whether their adventurers can scale a cliff, roll away from the strike of a magical lightning bolt, or pull off some other dangerous task. Anything is possible, but the dice make some outcomes more probable than others.

Dungeon Master (DM): OK, one at a time. Phillip, you’re looking at the gargoyles?

Phillip: Yeah. Is there any hint they might be creatures and not decorations?

DM: Make an Intelligence check.

Phillip: Does my Investigation skill apply?

DM: Sure!

Phillip (rolling a d20): Ugh. Seven.

DM: They look like decorations to you. And Amy, Riva is checking out the drawbridge?

In the Dungeons & Dragons game, each player creates an adventurer (also called a character) and teams up with other adventurers (played by friends). Working together, the group might explore a dark dungeon, a ruined city, a haunted castle, a lost temple deep in a jungle, or a lava-filled cavern beneath a mysterious mountain. The adventurers can solve puzzles, talk with other characters, battle fantastic monsters, and discover fabulous magic items and other treasure.

One player, however, takes on the role of the Dungeon Master (DM), the game’s lead storyteller and referee. The DM creates adventures for the characters, who navigate its hazards and decide which paths to explore. The DM might describe the entrance to Castle Ravenloft, and the players decide what they want their adventurers to do. Will they walk across the dangerously weathered drawbridge? Tie themselves together with rope to minimize the chance that someone will fall if the drawbridge gives way? Or cast a spell to carry them over the chasm? Then the DM determines the results of the adventurers’ actions and narrates what they experience. Because the DM can improvise to react to anything the players attempt, D&D is infinitely flexible, and each adventure can be exciting and unexpected.

The game has no real end; when one story or quest wraps up, another one can begin, creating an ongoing story called a campaign. Many people who play the game keep their campaigns going for months or years, meeting with their friends every week or so to pick up the story where they left off. The adventurers grow in might as the campaign continues. Each monster defeated, each adventure completed, and each treasure recovered not only adds to the continuing story, but also earns the adventurers new capabilities. This increase in power is reflected by an adventurer’s level.

There’s no winning and losing in the Dungeons & Dragons game—at least, not the way those terms are usually understood. Together, the DM and the players create an exciting story of bold adventurers who confront deadly perils. Sometimes an adventurer might come to a grisly end, torn apart by ferocious monsters or done in by a nefarious villain. Even so, the other adventurers can search for powerful magic to revive their fallen comrade, or the player might choose to create a new character to carry on. The group might fail to complete an adventure successfully, but if everyone had a good time and created a memorable story, they all win.

1. The DM describes the environment. The DM tells the players where their adventurers are and what’s around them, presenting the basic scope of options that present themselves (how many doors lead out of a room, what’s on a table, who’s in the tavern, and so on).

2. The players describe what they want to do. Sometimes one player speaks for the whole party, saying, “We’ll take the east door,” for example. Other times, different adventurers do different things: one adventurer might search a treasure chest while a second examines an esoteric symbol engraved on a wall and a third keeps watch for monsters. The players don’t need to take turns, but the DM listens to every player and decides how to resolve those actions.

Sometimes, resolving a task is easy. If an adventurer wants to walk across a room and open a door, the DM might just say that the door opens and describe what lies beyond. But the door might be locked, the floor might hide a deadly trap, or some other circumstance might make it challenging for an adventurer to complete a task. In those cases, the DM decides what happens, often relying on the roll of a die to determine the results of an action.

3. The DM narrates the results of the adventurers’ actions. Describing the results often leads to another decision point, which brings the flow of the game right back to step 1.

This pattern holds whether the adventurers are cautiously exploring a ruin, talking to a devious prince, or locked in mortal combat against a mighty dragon. In certain situations, particularly combat, the action is more structured and the players (and DM) do take turns choosing and resolving actions. But most of the time, play is fluid and flexible, adapting to the circumstances of the adventure.

Often the action of an adventure takes place in the imagination of the players and DM, relying on the DM’s verbal descriptions to set the scene. Some DMs like to use music, art, or recorded sound effects to help set the mood, and many players and DMs alike adopt different voices for the various adventurers, monsters, and other characters they play in the game. Sometimes, a DM might lay out a map and use tokens or miniature figures to represent each creature involved in a scene to help the players keep track of where everyone is.

The game uses polyhedral dice with different numbers of sides. You can find dice like these in game stores and in many bookstores.

In these rules, the different dice are referred to by the letter d followed by the number of sides: d4, d6, d8, d10, d12, and d20. For instance, a d6 is a six-sided die (the typical cube that many games use).

Percentile dice, or d100, work a little differently. You generate a number between 1 and 100 by rolling two different ten-sided dice numbered from 0 to 9. One die (designated before you roll) gives the tens digit, and the other gives the ones digit. If you roll a 7 and a 1, for example, the number rolled is 71. Two 0s represent 100. Some ten-sided dice are numbered in tens (00, 10, 20, and so on), making it easier to distinguish the tens digit from the ones digit. In this case, a roll of 70 and 1 is 71, and 00 and 0 is 100.

When you need to roll dice, the rules tell you how many dice to roll of a certain type, as well as what modifiers to add. For example, “3d8 + 5” means you roll three eight-sided dice, add them together, and add 5 to the total.

The same d notation appears in the expressions “1d3” and “1d2.” To simulate the roll of 1d3, roll a d6 and divide the number rolled by 2 (round up). To simulate the roll of 1d2, roll any die and assign a 1 or 2 to the roll depending on whether it was odd or even. (Alternatively, if the number rolled is more than half the number of sides on the die, it’s a 2.)

Does an adventurer’s sword swing hurt a dragon or just bounce off its iron-hard scales? Will the ogre believe an outrageous bluff? Can a character swim across a raging river? Can a character avoid the main blast of a fireball, or does he or she take full damage from the blaze? In cases where the outcome of an action is uncertain, the Dungeons & Dragons game relies on rolls of a 20-sided die, a d20, to determine success or failure.

Every character and monster in the game has capabilities defined by six ability scores. The abilities are Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma, and they typically range from 3 to 18 for most adventurers. (Monsters might have scores as low as 1 or as high as 30.) These ability scores, and the ability modifiers derived from them, are the basis for almost every d20 roll that a player makes on a character’s or monster’s behalf.

Ability checks, attack rolls, and saving throws are the three main kinds of d20 rolls, forming the core of the rules of the game. All three follow these simple steps.

1. Roll the die and add a modifier. Roll a d20 and add the relevant modifier. This is typically the modifier derived from one of the six ability scores, and it sometimes includes a proficiency bonus to reflect a character’s particular skill. (See chapter 1 for details on each ability and how to determine an ability’s modifier.)

2. Apply circumstantial bonuses and penalties. A class feature, a spell, a particular circumstance, or some other effect might give a bonus or penalty to the check.

3. Compare the total to a target number. If the total equals or exceeds the target number, the ability check, attack roll, or saving throw is a success. Otherwise, it’s a failure. The DM is usually the one who determines target numbers and tells players whether their ability checks, attack rolls, and saving throws succeed or fail.

The target number for an ability check or a saving throw is called a Difficulty Class (DC). The target number for an attack roll is called an Armor Class (AC).

This simple rule governs the resolution of most tasks in D&D play. Chapter 7 provides more detailed rules for using the d20 in the game.

Sometimes an ability check, attack roll, or saving throw is modified by special situations called advantage and disadvantage. Advantage reflects the positive circumstances surrounding a d20 roll, while disadvantage reflects the opposite. When you have either advantage or disadvantage, you roll a second d20 when you make the roll. Use the higher of the two rolls if you have advantage, and use the lower roll if you have disadvantage. For example, if you have disadvantage and roll a 17 and a 5, you use the 5. If you instead have advantage and roll those numbers, you use the 17.

More detailed rules for advantage and disadvantage are presented in chapter 7.

This book contains rules, especially in parts 2 and 3, that govern how the game plays. That said, many racial traits, class features, spells, magic items, monster abilities, and other game elements break the general rules in some way, creating an exception to how the rest of the game works. Remember this: If a specific rule contradicts a general rule, the specific rule wins.

Exceptions to the rules are often minor. For instance, many adventurers don’t have proficiency with longbows, but every wood elf does because of a racial trait. That trait creates a minor exception in the game. Other examples of rule-breaking are more conspicuous. For instance, an adventurer can’t normally pass through walls, but some spells make that possible. Magic accounts for most of the major exceptions to the rules.

There’s one more general rule you need to know at the outset. Whenever you divide a number in the game, round down if you end up with a fraction, even if the fraction is one-half or greater.