I am, work with, and know a lot of these people. Here are my thoughts:
1. Super-rich people typically start their own business and it becomes successful. This takes competence, luck, and a good idea.
2. Most other really rich people are involved in finance, typically hedge funds or private equity. But banking and regular investment management can also be a pathway. Being successful here takes competence and luck, but not necessarily any brilliant ideas. Best way to get started is a top-tier business school, but there are so many people who want to do this and only a small fraction will be successful.
3. Being a CEO or other C-suite member of a large and successful company can lead you there. IMO this requires extreme luck, competence, and some factors beyond your control. For example, you are more likely to become the CEO of a company like this if you are a tall male. If you are a short woman you are more or less screwed.
4. You could become a doctor or dentist or something like this and just be frugal for a number of years. If you are pulling in $500k and saving a third or more, you will get there eventually. This is probably the only pathway that does not require much luck, but still requires a lot of competence.
5. Marry it.
I'm sure there are more ways (someone mentioned high priced attorney). Anyway, the theme here is you need some combination of competence and luck. More of one means you need less of the other. Here is my example:
- Engineering degree from an average large state university. I was 3rd in my class. (competence)
- MBA from a very top business school. I was first in my class. (competence)
- Went to work for a large investment management company as an intern (luck to get the job since interviewing is quite random IMO). Performed well in the internship and got a full-time offer (competence). At the end of my summer a member of a very successful team quit suddenly and I went after his role (luck/timing). That team subsequently grew the assets it managed by a large amount, which was partly luck/timing with the asset class and also skill on the part of the portfolio manager I worked for (luck on my part).
- Said portfolio manager got a promotion as a result of his good work, which opened the door for me to takeover some of his responsibilities (more luck).
- I have performed at a very high level, making a lot of money for our clients and have consequently seen my compensation grow significantly (competence).