The alignment system in Dungeons & Dragons is a two-dimensional grid, one axis of which measures a "moral" continuum between good and evil, and the other "ethical" between law and chaos. Those characters that fall on one of the extremes are "good" or "evil", "lawful" or "chaotic"; in addition, there is a middle ground of "neutrality" on both axes, describing characters that are indifferent, committed to balance, or conflicted about the struggle between good and evil (or law and chaos). By combining the two axes, any given character has one of nine possible alignments:

Lawful Good Neutral Good Chaotic Good
Lawful Neutral (True) neutral Chaotic Neutral
Lawful Evil Neutral Evil Chaotic Evil

Certain classes are restricted in the sorts of alignment they can take. A paladin traditionally must be of lawful good alignment; rogues and barbarians are seldom lawful in alignment. Clerics and other priests must typically uphold the alignments favoured by their deities. Druids must be wholly or partially neutral in their allegiances. Assassins are usually evil. These restrictions have been somewhat relaxed in the 3rd edition of the Dungeons & Dragons game, although a character's alignment may shift if he acts in marked variance from his declared alignment.