Courtesy in the Realms
This one I see quite often. People, please be considerate to others and refrain from foul and crude language. It's something that I'm sure many people (including me) do not want to see when they are playing to relax and have fun. If you wouldn't say it in front of your kids, don't say it here. Also, if you have a dispute with another player, cursing at him is NOT the solution. It will only make matters worse.
It should be generally known that weapons should not be drawn at all times. This especially applies to cities and settlements, and also the farmlands, where it is generally peaceful. If there is some hostility going on, then it's permissable, of course, to defend oneself, but overall, please keep them sheathed. Remember also that the Flaming Fist HAS the authority to request that your weapons be put away, so please don't be all offended (whether In character or Out of Character) if that is asked of you.
Others Do Exist
Remember that even though you cannot see them, other people besides players do exist. For this reason, it may not be wise to discuss secret plans within a city market without whispering. If a Dungeon Master spots this, it is possible he/she may have a "person" overhear. Also, in regard to others being about, one should not stop to speak in the middle of roads and force others to walk around through the grass to get by. The roads are meant for traveling, so those who wish to idle should be the ones that step off to the side. This applies to both cities and roadways.
Animal companions, though they may be valuable to one's existence out in the wild, are entirely inappropriate in cities. Imagine what the commoner would think when he sees a person walking about in Baldur's Gate with a wolf or boar at his heels. Along the roads it would be more understandable, but do remember that it is not just adventurers who have seen these things before that travel. Keep in mind that many people would feel very uncomfortable, if not frightened, when having to be next to one. Good rangers, don't scare your neighbors! Evil ones would be more inclined to do so, and if it's within the personal roleplay of such a player, then fine. That doesn't mean the world won't react to such behavior however.
Shapeshifting is usually much worse than having animal companions or familiars following you around a City or Town. Commoners and guards dread seeing trees, elementals, and other such things scooting down the road. Druids, are servants of nature, and thus out in the woods, that is fine, it is even expected by their way of life. However, to walk along the road in shapechanged form is to ask for people to run away, for the Flaming Fist to attack you, and for adventurers to come to slay you. Goodly or neutrally aligned characters don't exhibit this behavior in front of everyone, risking giving a poor commoner a coronary..
For non-druids shapeshifting, the same applies ofcourse. Shapeshifting into devil or gargoyle form and walking down the road is explicity asking for trouble. There have been people who have done this, and then subsequently complained when the Flaming Fist attacked them. The simple answer is, don't do it! The guards or adventurers are are fully entittled to attack you without needing to give you a "roleplayed way out", in the sense of the regular player vs player combat rules. The Shapeshifted person still needs to give others such a "roleplayed way out" however.
Much of what was said above applies to this, but even more so. Balors, Undead, and such cannot be brought along without attracting notice. The guards will respond, and they will look for the summoner. Likewise, other players may also repond. I want to remind people that even if a Dungeon Master is not about, or player members are not online, the Flaming Fist continue patrol the roads. For sake of roleplay, please do not wander the cities and the tradeway with a balor or such at your heels.
Much as weapons should be sheathed in the city, spellcasting should not be done in such areas. Simple ones, such as light are permissible but please do not buff your character inside Baldur's Gate or while standing next to Jorn and his chickens. Obviously such places (as right next to the transition) would be appropriate to do so. In Beregost, for example, the exit is a little ways out of town and it is a good idea to prepare before exiting as one can be ambushed immediately, but don't turn yourself into a lighted Christmas tree in the market square.
Wal-Mart Employees Have Name Tags - Players Do Not
Too often players go entirely by the name tag above a character's head to determine who it is. While it may be handy to know, remember that people change clothing, wear helmets/masks, are covered in stone skin or bark skin, or are just plain UNKNOWN to you. Automatically using the name without thinking of any of the above mentioned reasons why NOT can sometimes spoil RP. Obviously everyone will make mistakes every now and then, but to help minimize this, try using the in game journal [ J ] to list who your character knows, especially if you play more than one character.
Outta My Way! Coming Through!
Sometimes other players act as road-runners. They come out of nowhere running full-tilt down the road. Of course, that is where the resemblance ends. Nobody honks a horn in this game, but many sure do fly right by. Now, this isn't so much the problem, because people are free to run until they drop. The problem lies in the fact that people are in such a hurry to get where they are going (probably grinding kobolds) that they will plow right through a group of people as if they do not exist. No "excuse me" beforehand. No "pardon me" afterwards. Though not major, this does become annoying. Make the effort to click the mouse a couple extra times to navigate around people instead of playing Faerunian Bumper Cars.
Sneaking can be very useful and good for roleplay if done properly. A ranger blending in with the wilderness, or a thief silently slipping into the shadows of a dark alley all work well. But do not extend this to unreasonable locations. For instance, do not try to sneak into the Flaming Fist Garrison or a Temple and assume nobody sees you because they are all NPCs. In all likelihood, even the best of stalkers could not go unnoticed in such places as these, and as such, it is bad roleplay to attempt something of the sort.
Now what is ninja looting? It can be done a variety of ways, but it's basically taking loot that is not yours without even roleplaying it, or snatching up as much of the goodies from a Dungeon Master's event rather than taking one apiece or rolling a sleight of hand vs. spot checks to see if one can actually do it beneath all those watching eyes. In other words, it is called taking the rewards of another's work and it should not be done.
This is walking up to a person who is battling a monster and killing it without any other reason than to just get the experience. There are plenty of spawns elsewhere. Of course there are roleplay situations in which helping another defeat something can be done, but those situations should be apparent at the time.
As in everything else, common sense should rule the day for roleplay. Just because something is not specifically mentioned here, doesn't mean that it's necessarily perfectly acceptable to do it. Think before you take action! Don't try to force others to roleplay situations if they do not want to go there. It takes little to no effort to mind the prefrences of other people and it really helps the overall online gaming experience.