1. Buy game
2. Play to Act II
3. Create new character with a different skillset
4. Finish Act II
5. Create new character only using one companion
6. Play to Act III
7. Create new character on hardest difficulty
8. Play to Act III
9. Wonder why you never finish the game.
10. Don't play for 3 months.
11. Think about making a new character
12. Repeat steps 2-12.

EDIT: Finally, it is done.
13. Finish the game