Taverns are often common backdrops for all types of RPG settings. There are many common tropes: bar brawls, mysterious patrons, the bar is a trap, etc. This list doesn't contain any of those. This list is more about backdrop. These are events that happen in the tavern that have nothing to do with the PC's, unless of course they decide to become involved.
Be warned. Taverns are dangerous places because PC's tend to go crazy there. Diving down ratholes you never meant them to explore and picking fights that you never intended them to fight. You must be prepared in advance for their shenanigans. You might try some of the following to be ready for whatever madness they bring to your plans. Remember, if you can't dazzle them with brilliance, then baffle them with bullsh*t. ;^)
Finally, if you came here for the 20 Events in a Crowded Tavern or Roadhouse Besides a Brawl, then you should know that this list is extremely generic. It is generic for two reasons. First, it was created to inspire you to create similar tavern encounters in your world that might develop NPC's or reveal little secrets to the perceptive PC's. Second, it is generic and simple such that it might be used again and again with easy substitutions. Without further delay, here is today's table. Happy Gaming!
A gambler wins another game of chance and boasts loudly to his opponents that none can best him or her.
The general store owner sits alone in a dark corner, sobbing into her/his ale.
The bartender takes a break to meet with a cloaked figure seated near the door.
A group of workmen start an arm-wrestling contest (best 2/3 Strength(Athletics) rolls).
A town guard patrol walks slowly through the bar, scanning the faces of the patrons.
A minor noble and his retainers drink quietly in one corner. Nearby a group of armed and cloaked men discuss populist topics in hushed tones while eyeing the noble and his group.
A cleric of the god of abstinence enters the bar and begins preaching against the evils of alcohol and calling for all good men to abandon drinking and vice.
A thief slinks quietly from shadow to shadow, stalking someone. Perhaps he is listening in on a conversation.
A bard sings popular songs and tells some favorite tales, as patrons request them. Otherwise, she simply plays quietly and scans the crowd for interest.
A knight and her followers loudly enter the tavern to celebrate a recent victory. They buy a round of ale for the house.
One gambler accuses another of cheating and a short argument ensues. Friends separate the angry gamblers and one group leaves the tavern.
A group of foreign merchants and caravan guards are getting loud and randy. A barmaid's tray is upset, and drinks fly as she is thrown to a table by a rowdy drunk. The drunk is quickly restrained by his friends and both the bar owner and the barmaid are given a platinum each for their troubles.
You notice a cloaked figure quietly threatening the bartender and then leaving the tavern.
Members of rival trade guilds insult and harass each other all in good fun.
A drunken and abusive town guard and his cronies are loudly telling stories and jokes belittling one of the races in the PC's group.
A drunken noble is in the tavern slumming and is making the moves on one of the PC's in the party.
A cleric of a god of indulgence enters the tavern and makes his way from table to table offering to bless the patrons' drinks for a small donation to the church.
A group of armed and cloaked figures sitting in the corner talk in hushed tones, while gesturing over a piece of parchment in the center of their table. One of the figures places a shield over the parchment anytime anyone comes near.
A pair of rival bards are having a battle of wits, song, dance, and comedy to the delight of the patrons to determine who the crowd wants to stay on for the next week.
An armored warrior enters the tavern and loudly calls out a name. The warrior hurls her gauntlet at the feet of the person now standing, then turns and walks out into the street.
You might also be interested in Tavern Workers and Shady Patrons. Tavern Workers contains 10 ready-to-go NPC's with jobs in a tavern and adventure seeds for your PC's. Shady Patrons has a nautical bent and also contains 10 ready-to-go NPC's with reasons to be in the tavern and adventure seeds for your PC's. Check them out and see if you'd like them them. As always, thanks for your support.