Lawful Good is known as the "Saintly" or "Crusader" alignment. A Lawful Good character typically acts with compassion, and always with honor and a sense of duty. A Lawful Good nation would consist of a well-organized government that works for the benefit of its citizens. Lawful Good characters include righteous knights, paladins, and most dwarves. Lawful Good creatures include the noble golden dragons. Lawful Good outsiders are known as Archons.
- Lawful Good characters, especially paladins, may sometimes find themselves faced with the dilemma of whether to obey law or good when the two conflict - for example, upholding a sworn oath when it would lead innocents to come to harm - or conflicts between two orders, such as between their religious law and the law of the local ruler. -- from Wikipedia "DnD Alignment"
Lawful Good is an alignment - reverent adherence to the law, combined with a respect for honesty and truth. It is diametrically opposed by Chaotic Evil.
Lawful characters can use True Law weapons, and are hurt by Anarchic and True Chaos/Absolute Chaos weapons.
Good characters can use Pure Good weapons, and are hurt by Unholy and Pure Evil/Evil Burst weapons or Taint of Evil items.