1. Your adventure starts off in a tavern
Problem: 99.8% of all adventures all start with characters meeting in taverns. If this were true, no taverns would exist considering the property damage that ensues.
Alternative: Try starting your adventure off in these places: a monastery, the stables or a vegan sandwich shop.
2. There is a corrupt authority figure
Problem: Players are so conditioned to the King/Queen/Duchess whatever secretly consorting with evil that they will immediately latch onto the idea and try and expose the truth.
Alternative: Make a benign NPC the big bad in your story. It could be the tanner, the blacksmith or someone who party members are conditioned to trust.
3. Violence is always the solution
Problem: While we role play to get out some of our baser emotions, there is a dangerous line if all problems can be solved at the end of a sword. Unless your world is the most horrible place imagined in existence, there should probably be repercussions if your players insist on putting someone to the sword each time they don’t get their way.
Alternative: Reward players for being diplomats or thinking their way out of problems using something other than their fists.
4. A dwarf has a battleaxe, your mage is a wimp
Problem: Yes, dwarves love to mine and drink and swing heavy weapons. Barbarians are rough around the edges yet can lift a plough horse. Rogues are sneaky little dudes with Snidely Whiplash mustaches or fetching beauties.
Alternative: How about a barbarian who wanted nothing more than to be a scholar? Or a dwarf who really wanted to be mage? Encouraging players to think outside the box on how their character interacts with world will create a closer bond with that character and make your world richer.
5. The search for X magic item
Problem: Quests are great and so are magical items, but we have all had to find the orb to stop Baroness Badblood one too many times. If you have players playing fetch from the get go, it will be difficult to get them to buy in fully when you come up with a truly amazing idea for a magical item.
Alternative: Make the mundane hard to achieve. Instead of starting out loaded to bear, make your players work for their first generic broadsword/halberd/flail. Chances are that after sweating dice rolls to obtain one they won’t be bitching about not having a +9 Sword of Smiting against Orcs.
6. An evil power is arising in X part of the world
Problem: Tolkien is great, which is why 99% of all fantasy is ripped straight from Tolkien. Perhaps the most borrowed upon trope is Sauron i.e. an evil presence manifesting itself in the world. Unless you plan to write a pre-script that covers thousands of years of history, you big bad is gonna come across as a discount Sauron.
Alternative: Turn the concept on it’s head an make your players outcasts in their own society. What if they are considered evil (even if they are not) just for being who they were? A daily fight for survival keeps the parties on their toes and working together as a group.
7. Your players get too powerful too quickly
Problem: If your players have managed finished their first adventure and have managed to kill a god, well you might be holding their hands a bit too much. It’s the Superman conundrum, once they have killed a supreme big bad, there isn’t much adventure left to be had.
Alternative: Make lower level bad guys much much harder. Have kobolds give your players a run for their money. Make them think tactically and actually lose if they just go in swinging, it will make for a better play session.