The Relative Evil Scale

This guy didn't multiclass paladin.

During my undergraduate years I wrote for a detective radio drama that aired once a week with a brand new mystery.  When it started out things were pretty simple; bad guy shows up, detective figures him out, bad guy goes to jail.  As this started to slowly begin to feel stale the other writers and I played around with adding longer lasting characters and plot lines without a whole lot of concern for tone.  Then we realized that we had made a terrible mistake.  As the episodes went by our villains kept getting meaner and meaner as our main character started getting more and more humanitarian.  We can't have a sparkly clean hero!  This is a 1930's noir for crying out loud!

We sat down one day to discuss this weird change in tone and to try to figure out how to fix it.  What we came up with then is something I now do every time I am running a campaign.  It does an excellent job preventing alignment creep and can even be used to avoid stereotyping a specific class of character as being always good or always bad.  I have come to call it the Relative Evil Scale.  

Making Your Own Scale 

Turn a piece of notebook paper landscape style and draw a line horizontally across it thus bisecting the printed lines on the paper if there are any.  At one end of the line write 'Most Evil' and at the other end write 'Most Good.'  Although you could theoretically add a Chaos/Law field the opposite way, I tend to be going purely for simplicity.

Now think of your most evil, most despicable character you would include in the game.  Basically this is where you are drawing a moral line in the dirt that determines in part the grittiness of your plot.  You shouldn't (without thinking very seriously) pass this character in terms of evil.  In our radio show we put a serial killer who had been much darker than any other character we'd included.  If we'd made this chart from the beginning, he probably wouldn't have been included because he was darker than our original Big Bad Guy mob-boss.  This character's name goes on the line next to Most Evil.  In all likelihood, (s)he doesn't share this line with anybody else.

Now think of your least evil, most good, most honorable, most giving character that you would include.  Your instinct may be to write down one of the heroes, but let's get real here for a second.  Unless you have a VERY abnormal PC party, the "heroes" of the game likely aren't good enough to bookend your scale.  They go around killing, looting, and stealing in the service of good, but using methods that aren't always nice.  I'd reserve this for someone who is untarnished as you allow in your world.  We had a District Attorney that was our absolute top guy and perfectly willing to give every last bit of himself to save the city he cared about.

This now is your scale of good to evil.  Unless you think very carefully, don't add anyone further from average than these two people.  This is where things get good.  The D.A. that I mentioned was the best guy around, but he was still a point of grey.  In one episode, we had him sucker punch a suspected perpetrator and then beat him unconscious when pushed too hard.  Any character we introduced after making the sheet had to have at least that level of Evil in them.  On the same token our Big Bad Mob Boss had little things that made him human; he cared about family, he occasionally did good things.  Therefore we can't have someone purely evil.

Application

So you've got your scale with two people on it.  Not very helpful yet.  Now as you begin to add characters into the game, start tracking where they are relative to each other.  Want to add another villain?  Put him on the scarier end.  Want to add someone really nice?  On the good side.  Maybe your PCs will stick close to one side or the other and that's alright, but you can do things to keep people in those interesting grey areas.  In some cases the scale may be REALLY wide (epic fantasy with Good versus Evil on the scale of The Wheel of Time or D&D come to mind) or it may be REALLY narrow (noirs, some urban fantasies, Paranoia).  It may tend more towards the side of good (realistic settings with more or less human characters) or it may tend more towards the side of evil (Evil vs Evil campaigns, Warhammer).  Looking at your scale can help you draw out in a more meaningful way the Best and the Worst your world has to offer.

I also use my Relative Evil Scale when I'm introducing characters to avoid making NPCs especially too similar.  In one game I played every character who displayed any noble blood was going to end up being evil.  If you've got a Relative Evil Scale just be sure that for each relatively evil noble you place that you add a relatively neutral or good one.  Guards also suffer from this terribly and on the opposite side frequently sit farmers and preachers.  This will all depend on your setting; maybe you are in a dystopia and nobles should be evil!  Maybe priests are the be-all-end-all of goodness!  That's okay, but this tool can help you point out to a player, "I appreciate the fact that you want to sacrifice your victims on giant altars of doom that suck their spirits down into an eternal abyss, but even the end boss has a family that he loves very much."  It's all about keeping tone consistent.