evil does not equal psychotically stupid
First off, I have both played an evil PC and GMed an evil campaign. There are no problems doing this if the people playing are decent RPers and reasonably mature. Evil is all about putting yourself first, sometimes at the expense of others. It does not necessarily denote a complete lack of ethics or morals, but instead an often twisted version of what most people would find to be normal or a willingness to occasionally ignore your misgivings about an act. Playing a PC that walks into town and slaughters a shopkeep isn't evil, he's psychotic. Even a CE character has to realize there are repurcussions to their actions, and blatently slaughtering townsfolk is likely to bring the local paladin down on you in a hurry and end your bid for wealth and power right there. A LE PC might try to swindle the shopkeep, by trading defective goods. A NE PC might give him currency that he knows has been diluted with base metals or shaved. A CE PC would have no qualms about breaking in that night to steal what he wanted (or take "ye olde five fingre discounte" if the item is small enough).
The evil game I ran featured the PC's as members of an assassins guild. The players were mostly NE and CE, but it sure didn't mean they went around indiscriminately killing and looting the local populace. Did they do despicable acts, heck yeah they did. They killed for money, they were generally ruthless with those that opposed them, and were genral scumbags. I think the worst that happened is one of the CE guys tortured someone for information (the NE PC who was with him left the room, sickened by the procedure). But they also did their best to stay under the radar of the local authorities, and had one of them decided it was more worthwhile to kill a shopkeep than pay for his services even though they could usually afford what they wanted, they would have found themselves ousted by the group quickly and very likely in a very permanent and lethal manner.
First off, I have both played an evil PC and GMed an evil campaign. There are no problems doing this if the people playing are decent RPers and reasonably mature. Evil is all about putting yourself first, sometimes at the expense of others. It does not necessarily denote a complete lack of ethics or morals, but instead an often twisted version of what most people would find to be normal or a willingness to occasionally ignore your misgivings about an act. Playing a PC that walks into town and slaughters a shopkeep isn't evil, he's psychotic. Even a CE character has to realize there are repurcussions to their actions, and blatently slaughtering townsfolk is likely to bring the local paladin down on you in a hurry and end your bid for wealth and power right there. A LE PC might try to swindle the shopkeep, by trading defective goods. A NE PC might give him currency that he knows has been diluted with base metals or shaved. A CE PC would have no qualms about breaking in that night to steal what he wanted (or take "ye olde five fingre discounte" if the item is small enough).
The evil game I ran featured the PC's as members of an assassins guild. The players were mostly NE and CE, but it sure didn't mean they went around indiscriminately killing and looting the local populace. Did they do despicable acts, heck yeah they did. They killed for money, they were generally ruthless with those that opposed them, and were genral scumbags. I think the worst that happened is one of the CE guys tortured someone for information (the NE PC who was with him left the room, sickened by the procedure). But they also did their best to stay under the radar of the local authorities, and had one of them decided it was more worthwhile to kill a shopkeep than pay for his services even though they could usually afford what they wanted, they would have found themselves ousted by the group quickly and very likely in a very permanent and lethal manner.