A standard roleplaying environment: the tavern. This is another easy one to create in your own home, providing you have a large enough group of roleplaying friends. Let us assume your PC group is no larger than five, and that the rest of your friends can be NPCs. Let us also aim for an exceptionally seedy and unscrupulous city tavern.
First of all, prepare your NPCs. Generate some random NPCs before gameplay starts, and provide your friends with the bare character details and a pile of clothes borrowed from a local dramatic society or theatre. It is up to them to decide how to play the character they choose, and what their relationships will be with the other characters and NPCs. Give them a good ten minutes to sort themselves out. If there is some specific piece of information the PCs are looking for when they come into the tavern, or some particular NPC (maybe a famed thief) make sure that person is represented or that at least one NPC knows that piece of information.
To make the setting authentic, cut the electric lights and replace them with candles. Drape rugs over those anachronistic items like televisions or hi-fis. Soft comfortable chairs should be arranged into the bar: lined up with their backs facing into the room. The ledge created by the seats can be explained away as being a platform for dwarf bartenders. Arrange around the room a couple of small wooden tables (or if you have none, use cardboard boxes covered with rugs) with crappy old wooden chairs, and encourage your clientele of NPCs to make themselves at home. All the need for GM-planned encounters and vignettes is removed because the NPCs provide them naturally.
Flagons can be a problem, though usually a couple of tasteless pewter mugs can be obtained cheaply at a car-boot sale. A smoke machine can be used to create a thick, unpleasant atmosphere if required. If it fits the character of your tavern, board up your windows with a couple of old planks of wood.
Decide on a regional tavern accent before you start, because otherwise everyone will have different (unconvincing) voices. A unity in accent gives a degree of believability to the set-up.
Hang a couple of random artefacts around the place, maybe an ornamental Japanese sword, and come up with a backstory of how it came into the tavern (perhaps a famous explorer once came here, got drunk and forgot his valuable artefacts which have since been incorporated into the tavern’s decor).
A bar-brawl has to be well-choreographed. Before starting, rehearse such an incident with your NPCs. A good strategy is as follows.
Assume we have 8 NPCs/PCs plus a bartender. The bar brawl may erupt in any way you choose, but once it is under way, I’d recommend using these rules to create an ordered chaos you can control (the rules are vaguely based on that ubiquitous cellular automaton “The Game of Life”...).
#Split the NPCs into four groups of two and divide the bar into four areas: three in front of the bar, one behind. Each fighting group occupies one area at any one time.
#Any group of four must split into two groups of two.
#If more than one person is in the same area they must fight or try and break up any combats going on there, thus becoming involved themselves.
#If one person is left alone in an area they must move on to another.
#Once someone has been hit more than three times they must stagger backwards, fall and “lose consciousness” for a minute. For that time they do not count as a participant.
#No person may spend more than two minutes in a given area, unless they are unconscious when the two minute deadline is up.
It’s not a completely rigorous set of rules and there may be unconsidered exceptions, but it’ll probably work quite well. I’ve not yet had an opportunity to try them out…
Practice leaping over the bar, practice pretending to hit without actually hitting, practice yelling foul language and hurling opponents to the floor while they practice falling without hurting themselves. All sharp or breakable objects should have been removed from the room, save possibly for some (very) cheap crockery bought for the purpose of smashing.
A couple of special stunt moves (to be attempted only after a lot of rehearsal and with very cheap equipment) would involve whirling a chair around one’s head and overturning a table.
All you need to complete the tavern is a crackling fire and a cardboard/wood sign bearing a suitably cheesy name like “The King Fred” or “The Puce Dragon”. With a little time and paint you could also make a window to stick on the outside and a window to stick on the inside of the room. On the back of the outside window, you could paint a broken window, and (in the aftermath of a brawl) turn it around to display this broken window.
One thing which happens relatively often in fantasy bar-brawls is that the tavern is set alight. Obviously this is not easy to simulate and I wouldn’t recommend trying. Maybe, if you felt it completely necessary, you could increase the output from a smoke machine to fill the room with smoke. Maybe you could use a yellow/orange filter on a strobe to give the impression of flickering flames. But you’re probably safest (and cheapest) using your imagination.