<prompt> Human: I want to describe a strategy that a friend of mine has adopted, and get general feedback on pros and cons. She is very focused on real estate, as it represents tangible property. Broadly, her strategy seems to be to accumulate as many houses as possible prior to retirement, with the plan of having them mostly or totally paid off, and living off of either the rent income, or using the gains on the properties over 30 years as the nut from which to earn income in retirement.Shes got a good job as a project manager, I estimate she probably makes 90Kyear in a medium sized US city. Shes pretty frugal and doesnt spend that much on herself and her family. She began by buying a small house. After 2 years of payments, she began renting it out, and moved her family in with her parents. I doubt that the rent covered the mortgage, but she was living without cost with her parents so the net was that she was paying very little for progressively owning more of a house.Eventually she bought a second house and moved into that. Now shes carrying two houses, and she has plans to buy a third.Im wondering about the wisdom of this strategy. Its possible that her parents are giving her big chunks of cash to make down payments large enough that she can carry more mortgage payments simultaneously over time.Just off hand, it seems to me that this strategy carries a lot of risk with it. Her assets are basically in one sector housing and only in one geographic area. It seems like a very safe bet the houses will be worth more after 20-30 years, but how much more as compared to what an index fund would have done?Any comments or observations about this strategy would be appreciated, including how you can swing having 3 mortgages at once, with a modest income, without a big cash infusion to drive the mortgage payments down.  <response>: Real estate investing can work for many people. Ive also seen people buy fixer-uppers with the intent to renovate... and then it goes nowhere.The most consistent advice Ive seen is spend 10x the amount of time and money on educating yourself in real estate matters vs. time and money spent looking at the market. Check out rrealestate and 