|Cleric, level 12, NG|
1. The adventure area is watched by a powerful force, which will smite anyone who practices unauthorized violence within.
2. The players are aided by a powerful NPC, who will turn against them for philosophical reasons if they take life.
3. Due to complicated intrigue, the party is running an operation against people from their own side, whom scruples forbid them to kill. Perhaps the opposition is guarding someone you know to be an enemy agent; perhaps it's a false-flag mission calculated to shift blame.
4. Captured once, the group has sworn a powerful and binding oath to show their foes the same mercy their captors showed them.
5. The point of the adventure is to bring them back, alive and unharmed ... people wanted for questioning or imprisonment, creatures wanted for a menagerie or research or breeding.
6. Innocent people and animals have been possessed or deluded by some hostile force. You need to incapacitate them without killing, on the way to destroying the force and releasing its hold on them.
How can a normal adventure scenario packed with hostile beings yield to a non-violent strategy?
First, let's look at the tools at hand. Most obviously, spells such as sleep and hold person don't need to be followed up by the usual slitting of throats.
Some systems, too, have rules for non-lethal combat. My own house-rule is simple: weapons optimized for non-lethal blows (fists, staffs) do full nonlethal damage, while other weapons, striking with haft, pommel or flat of blade, do half, rounded up. This only works against beings with a normal, animal anatomy. When a nonlethal blow takes a foe to zero or lower hits, it is incapacitated, semiconscious but unable to move, cast or strike for 1d6 combat rounds. For the aftermath, ropes or manacles are a must.
But depending on the terms of the nonviolence, you may still be able to get in a fight to the, well, destruction. Many of the scenarios above would allow players to remove non-sentient creatures from the equation; green slimes, golems, maybe even guard dogs are fair game, if your only concern is for the welfare of humans and other intelligent beings.
For intelligent and semi-intelligent creatures, there's also a wide range of psychological tricks: intimidation, fright, appeasement, negotiation, confusion, deception. All but the most intelligent and aware foes should be susceptible to at least one of these. If there are no skills for social interaction in the game, a combination of Reaction rolls, Morale rolls, spot checks for Charisma, Intelligence or Wisdom, and common sense should help judge any kind of trickery.
While nonviolent strictures on the players can increase the challenge of an adventure or even a single encounter, there are also ways to set up an adventure so that the thought of violence never even enters into the scene. More on that in the next post.