Somewhat related to the thread What if Your Alignment Could be Classified. I am interested in how people use alignment in their games, or if they use them at all. Is the concept of alignment limited to games like Dungeons & Dragons and Pathfinder or are there other systems that utilize similar concepts?
One of the reasons I ask is because I recently ran across this quandary in one of my online games where a character who was "Neutral good" Essentially murdered two halflings in order to use them in a blood ritual in order to save the other members of the party who were suffering from a magical disease. Was this action in line with his alignment? As the GM should I have told the player no, he could not take this action because this was not consistent with a "Good" Alignment?
In the end, before he took the action I explained that if he did his alignment would shift to True Neutral. Normally I don't place much stock in alignment at all but when working with a system that does utilize alignment in some of its mechanics (Such as spells to detect certain alignments), it does have an impact I feel.
Alignment can be a tricky beast in my opinion. It can be used to limit players and their character or it can be used more as a guiding principle; sometimes it is not really used at all. Part of the problem (If you want to call it that) with games like Dungeons & Dragons or Pathfinder that do utilize alignment is that there are certain elements of the mechanics of the system that are somewhat dependent on alignment. Certain spells, for example detect alignments or can be used to protect the caster or an ally from certain alignments (Protection from good/evil).
As a GM I don't want a player to limit themselves or the development/actions of their character simply based on their alignment, which can happen when the concept of alignment is over simplified. The lawful good character being completely incapable of doing something wrong, for example, and the GM telling the player "No, you can't do that because your character is lawful good." However, I also see it misused so to speak, by the players as well; for example a player listing the character as lawful good but then joining a party full of what are essentially murder hobos that want to kill everything and everyone that they come across and take their loot.
Assuming that a lawful character will always follow the letter of the law in whatever culture they find themselves in, or a chaotic character being completely incapable of adhering to any rules, or the Chaotic Neutral character that is so random they just start attacking the other party members for reason other than "I'm just playing my alignment" Is an oversimplification of alignments in my opinion. Many times this leads players to simply mark their characters as True Neutral so that they can pretty much do whatever they want without feeling restricted by the character's alignment, but at what point do they stop being neutral and cross over into one of the other alignments?
I guess my point is that a lawful good character is not all the time lawful, nor is he/she all the time good; and both of those concepts can often vary in their interpretation depending on what culture is examining them. What is good and lawful to one culture may be evil and unlawful to another, so what standard do we use? Should we bother with alignments at all, or simply get rid of the concept of alignment along with whatever mechanic in a system that deals with this concept?
"All men can see the tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." -- Sun Tzu, The Art of War
Polar alignments are mostly exclusive for Dungeons & Dragons and its descendants, although many other games have mechanics that limit a character's activities to a code or beliefs. In Dungeons & Dragons evil and good are tangible things; you can talk to an angel or a demon with the right campaign. Most other games do not have this ideological strata.
I usually ignore alignments, honestly. If the player plays in-character, I can wing most of the other mechanics. I never enjoyed putting the players of paladins in moral tight spots more than once or twice in a whole campaign. Now, that does not mean that there are no consequences for behavior that go against a person's character. If a paladin clearly acts against the dictates of her faith, loss of benefits as the character's patron recoils from the aberration. There are also laws and realistic reactions from the world around them that may be brought in for certain behaviors.
One thing about alignment, and you may consider this as a bit of a gaming convention, is that alignment never excuses behavior in or out of character that damages the gaming experiences for others. You used the example of a chaotic character who "Logically" Decides to murder his companions when given a chance. When confronted with that situation, I have always taken the position to give the player a chance to get their character to work better with the group, or the player is asked to leave the group. Selfish play like that ruins the game for everyone.
Alignment is a little like having a script to follow in a play, as opposed to coming up with your role and lines on the fly. It's fine, but I'd rather reward a player for good role-play than use their alignment as an excuse to punish them.
Generally, I think most players do not follow alignment. When it comes to saving their character alignment goes out the window. Could be that is how it is for most of us in real life situations too. If there were a game where your character had to protect family / children then I think alignment would not even matter. Still I like seeing the chosen alignment of characters, it tells me more about the player than the character ;).
I play in some Role-playing Games here that don't have any alignment. I think its best that way because you're able to play the style you want without having to consider "Am I playing my character's alignment?"
I try to play the alignment of my character when I can mostly when its quiet time (No combat). Its a good opportunity to give trouble or show strong attitudes so other characters can know [your] character is not just a push over. ;)
Most role-players tend to have a hard time taking their own morals and ethics out of the game and role-playing the character for whatever alignment he is, for instance, chaotic evil. I generally will choose an alignment I know I can handle rather than trying to be too fa away from my own comfort zone.