[...] I am not terribly well versed in DnD, but I am pretty especially Lawful vs Evil has less to do with being "good or bad" in moral sense, but more of "control vs impulses". Laws can be good or bad. It's more about your character wanting to follow rules, or him doing whatever feels good at the moment.
That's why there are two separate axes. Good vs Evil and Law vs Chaos. There is no "Law vs Evil" axis; you can easily be both, just one, or neither.
Capital G-Good and capital E-Evil are fairly well defined in the D&D universe. Good is, practically by definition, what the Good Gods espouse and represent. Selflessness, kindness, benevolence, mercy. There are entire planes of existence of Good creatures, and if they don't act like they should, they literally turn into different creatures to reflect their alignments. Good creatures can still cause harm (e.g., LG creatures working towards "The Greater Good"), but their intention is to help others. Same for Evil: selfishness, cruelty, hatred, and all that.
Similar to how @GM4Him is saying "God's Law is Good and Right," in D&D "The Good Gods' Patheon is [by definition] Good" There's just nuance in how exactly each of those Gods goes about achieving Good; which method is Right (e.g., helping others via charity vs killing evildoers to prevent future harm).
