Good Debt vs Bad Debt: Kiyosaki's View and the Mainstream View

Kiyosaki's definition

Robert Kiyosaki describes debt in cash-flow terms:

Good debt is debt that someone else pays for you. Typically that's a mortgage on a rental property, where the tenant's rent covers the repayments, or a business loan that generates more profit than it costs.
Bad debt is debt you pay for yourself, out of your own income: credit cards, car loans, consumer loans, and arguably the mortgage on the home you live in.

He's openly comfortable with large amounts of good debt, and has said publicly that he carries very large debts as a deliberate strategy.

Most financial planners use a different test: cost and purpose.

Generally reasonable: low, ideally fixed-rate debt used for something that holds or grows in value or raises your income. Examples are a sensible mortgage, a business loan with a clear plan, and some education loans.
Generally harmful: high-interest debt used for consumption. Credit card rates are commonly 20% or more a year, and buy-now-pay-later and payday loans can be worse.
Priority rule: pay off high-interest debt before investing, because few investments reliably beat a 20% interest rate.

Consumer debt for things that lose value (gadgets, holidays, cars beyond your means) is bad debt in both views.
Debt should have a purpose and a plan for repayment.
A loan that produces more than it costs can build wealth.

How much is safe. Kiyosaki's approach tolerates high leverage. Mainstream advice treats high leverage as a major risk, because when rents fall, rates rise or a tenant leaves, "good debt" becomes debt you pay yourself overnight.
The family home. Mainstream advice usually treats a sensible mortgage as acceptable debt. Kiyosaki counts it as bad debt because it doesn't pay you.
Paying debt off. Mainstream advice values being debt-free. Kiyosaki sees paying off good debt early as a waste of leverage.

Ask five questions before you borrow:

What does it pay for? Something that earns or grows, or something you'll consume?
What does it cost? The interest rate, and whether it's fixed or variable.
Who really repays it? You, from your salary, or an income stream it creates?
What if things go wrong? Could you keep paying if the income stopped for six months, or if the rate went up by 3 percentage points?
Is there a buffer? Do you have an emergency fund that isn't itself borrowed?

A loan that passes all five is debt both dads could live with.

Robert T. Kiyosaki with Sharon L. Lechter, Rich Dad Poor Dad (1997), and Kiyosaki's later books and public statements on debt.
Typical credit card rates: published averages from central banks and consumer finance surveys, which have commonly been above 20% APR in recent years.