Smoke Screen (CR 4)
Story
This encounter consists of 6 bandits, mercenaries, or bounty hunters looking to kill or capture a specific npc. This could be someone in the party's watch, or somebody that just happens to be at the same inn as the party during another adventure. In the night, the bandits set fire to the inn, and wait for the fire or smoke to kill their quarry or flush them out to be killed in the ensuing panic. The burning building aspect is handled as a trap with a secondary environmental effect.
Tactics
The encounter presumably starts with the characters waking up to the cries of smoke and fire. Once out of their rooms, they will have to contend with both, and any DM may feel free to include fallen bystanders that need rescuing as they work their way out of the building. Those that want to jump from the windows may, but must deal with a 20ft fall onto the ground.
Outside, the mooks are waiting for their target to arrive. Once spotted, they will begin to attack immediately, starting with either their remaining alchemist's fire or javelins, before closing with swords. Those that oppose them will be met with a similar attack. If more than half are dead or incapacitated, the mooks will attempt to flee into the nearby terrain or escape on horseback, as appropriate.
Burning Building
The burning building has 2 dangers: Fire & Smoke. There is fire and smoke on the second floor, but only fire on the first.
Effect 1 (Fire): Characters at risk of catching fire are allowed a DC 15 Reflex save to avoid this fate. If a character's clothes or hair catch fire, he takes 1d6 points of damage immediately. In each subsequent round, the burning character must make another Reflex saving throw. Failure means he takes another 1d6 points of damage that round. Success means that the fire has gone out—that is, once he succeeds on his saving throw, he's no longer on fire.
A character on fire may automatically extinguish the flames by jumping into enough water to douse himself. If no body of water is at hand, rolling on the ground or smothering the fire with cloaks or the like permits the character another save with a +4 bonus.
Those whose clothes or equipment catch fire must make DC 15 Reflex saves for each item. Flammable items that fail take the same amount of damage as the character.
Effect 2 (Smoke): A character who breathes heavy smoke must make a Fortitude save each round (DC 15, +1 per previous check) or spend that round choking and coughing. A character who chokes for 2 consecutive rounds takes 1d6 points of nonlethal damage. Smoke obscures vision, giving concealment (20% miss chance) to characters within it.
Map Key
Grey Square (Connected) - Stone Wall.
Brown Square (Connected) - Wooden Wall.
Brown Squares or Rectangles (Unconnected) - Table or Bench
Brown or Green Sliver - Door or Hinged Bar Lid
Parallel Black Lines - Stairs
Closed off Wooden Area on 1st Floor - Bar
Grey Outcropping into upper left room - Hearth for Common Room & The Kitchen