1) The bloke you are writing about, well, he has to overcome some stuff and succeeds. Examples: Star Wars, Lethal Weapon, The Road, Pride and Prejudice, Neighbours, Lethal Weapon 2.
2) The bloke you are writing about, well, he has to overcome some stuff and fails. Examples: The Illiad, Lethal Weapon 3 and 4, The Bible 2: The New Testament.
So, what does this really tell, us? Yes, plot doesn't matter, all you need are obstacles. They can range from hurdles to Madge Bishop but they are what make a story great, random obstacles that confound your hero until he succeeds/fails completely. Some of my favourite hurdles are:
- Madge Bishop
- Armies of zombie kittens
- Having to go to work
- Michael Gove (keep him 'til the end and make him the puppet master bad guy)
- Paper cuts
- A one way system
Hopefully these will help fire your imagination!