Re: Detect Evil:
It's a pain to arbitrarily judge. I find the spell to be tantamount to a super radar.
Evil NPC eating lunch. "He's evil, smite him!!!"
then what? the government will bring up that the pc's disobeyed the law. The PC's returns a "ask a priest to detect evil on him". Makes for a most annoying circumstance.
I have yet to find a ruling or house rule that will cover this issue.
I have run the spell as detecting evil alignments since day 1 and it's never presented a problem in any of my campaigns. Simply being evil (of low magnitude--faint, moderate, or dim evil auras) is rarely an excuse to smite someone. I've always made it clear that there are lots of evil people out there some of whom cheat their customers, some of whom betray their friends, some of whom promise their heart to many women (or men) without ever meaning it, and some of whom are hungry for power. Those don't all deserve death and even for those that do, it's rarely practical to simply smite them then and there on that basis. (If the PCs tell the law--"Detect Evil on him, you'll see", the most likely response is "It's a little late for that now, isn't it--need I remind you that there's no law against being evil but there is one against murder. Will you come peacefully?") The other good reminder for PCs is that weak evil could be:
1. A 2nd level evil cleric
2. A weak polymorphed evil outsider
3. A 10 hd disguised dragon
4. A 10th level necromancer
5. A 10th level evil fighter
6. A first level evil commoner
Smiting first and asking questions later may work (absent all legal considerations) with options 1, 2 and 6 but options 3, 4, and 5 are likely to result in a TPK.
Moderate Evil is even worse. It could be:
1. A 12th level evil fighter
2. A weak demon or devil
3. An 8th level vampire fighter
4. A 20th level necromancer
5. A 10/10 fighter/Ravager
6. A 7th level evil cleric
7. A 15th level aristocrat who's known for betraying friends
8. A 12th level expert who's prosperity and location on the city council is due to his ruthless and underhanded business practices.
So smiting moderate evil first and asking questions later could be a winable fight (2, 6), an action with tremendous political reprecussions (7, 8), or suicide (4, 5, 6).
Detect Evil may be a super radar but its very sensitivity in 3e inclines it towards false positives. It may very well detect bad guys but it doesn't limit itself to "bad guys you're looking for", "bad guys you can handle", "bad guys no one cares if you kill", or "bad guys who've done anything deserving of death." All it detects is evil alignments--and in my campaigns, that's about 15-50% of any given human city.
Again something constructive:
#25The Evil that is Out of Reach
The wizard PC is shopping at the general store and the owner (a powerful man who owns a trading company and is one of the duke's most noted supporters) offers him some gold if he will identify an item for him. When the wizard picks up the item, to identify it, he realizes that it's a +2 sword but merely touching it gives him a negative level. The owner observes the wizard's discomfort (which confirms to him that his sword is infused with Unholy power), thanks the wizard for his effort, pays him well for his trouble and assures him that he'll deal with the sword appropriately. The owner doesn't seem to be harmed in the least when he picks up the sword. What does the PC do?
(In this example, the PC has reason to suspect that the owner is evil--especially if the PC is neutral good, lawful or chaotic characters could draw other conclusions--but no proof.)