Ok, this is for the GMs.
Recently, my gaming group bundled their characters into a boat and sailed away to a part of the continent they haven't been to yet to go be introduced to the next part of the plot. Before leaving, they spent almost every gold piece they had buying weapons, swimming gear, and like three months of preserved food wrapped in oil skins and bundled together in a fishnet with bouys. When I finally caved and asked what the heck they were doing, they replied in unison, "boats sink in your games."
And it's true. Get on a boat in one of my campaigns and the likelihood is you're not going to get where you started out going.
I started a campaign once where the characters all got on a boat, which was promptly (in real time, a couple days in game time) set upon by a roving magical storm and evil fish baddies. Halfway through the battle, the ship lurched and shook violently, and everyone was knocked unconscious. When they woke up, they found themselves and the entire ship smack dab in the middle of a desert.
Now that it's been pointed out to me, I've decided to go with it. If it's what the players expect, they'd be disappointed if something didn't happen.
So ... what's your frequently used/abused trope and do you make a conscious effort to avoid using it or do you just accept that it's part of your oeuvre?