Before the game begins, each player creates his or her player character and records the details (described below) on a character sheet. First, a player determines his or her character's ability scores,[30] which consist of Strength, Constitution, Dexterity, Intelligence, Wisdom, and Charisma. As of 4th Edition, players generally assign their ability scores from a list or use points to "buy" them.[31] The player then chooses a race (species) such as Human or Elf, a character class (occupation) such as Fighter or Wizard, an alignment (a moral and ethical outlook which may have a Good or Evil component, a Lawful or Chaotic component, or something in between), and a number of powers, skills and feats to enhance the character's basic abilities.[32] Additional background history, not covered by specific rules, is often also used to further develop the character.[33]

During the game, players describe their PC's intended actions, such as punching an opponent or picking a lock, and converse with the DM in character—who then describes the result or response.[34] Trivial actions, such as picking up a letter or opening an unlocked door, are usually automatically successful. The outcomes of more complex or risky actions are determined by rolling dice.[16] Factors contributing to the outcome include the character's ability scores, skills and the difficulty of the task.[35] In circumstances where a character does not have control of an event, such as when a trap or magical effect is triggered or a spell is cast, a saving throw can be used to determine whether the resulting damage is reduced or avoided.[36] In this case the odds of success are influenced by the character's class, levels and (with the 3rd edition) ability scores.[37]

As the game is played, each PC grows and changes over time as they gain experience. Characters gain (or sometimes lose) experience, skills[38] and wealth, and may even change alignment[39] or add additional character classes.[40] The key way characters progress is by earning experience points (XP/EXP), which happens when they defeat an enemy or accomplish a difficult task.[41] Acquiring enough XP allows a PC to advance a level, which grants the character improved class features, abilities and skills.[42] XP can also be lost in some circumstances, such as encounters with creatures that drain life energy, or by use of certain magical powers that require payment of an XP cost.[43]

Hit points (HP) are a measure of a character's vitality and health and are determined by the class, level and constitution of each character. They can be temporarily lost when a character sustains wounds in combat or otherwise comes to harm, and loss of HP is the most common way for a character to die in the game.[44] Death can also result from the loss of key ability scores[45] or character levels.[46] When a PC dies, it is often possible for the dead character to be resurrected through magic, although some penalties may be imposed as a result. If resurrection is not possible or not desired, the player may instead create a new PC to resume playing the game.[47]



Taken from Wikipedia