Demo mode runs the same maths with play money. It is the cheapest way to find out whether you actually enjoy the game before it costs anything.
What the demo is
A version of the game with an imaginary balance. The probabilities, the payout table and
the multipliers are identical to the real-money version — studios use one engine for both.
What differs is only that nothing is at stake.
What it is worth doing
Drop several hundred balls at high risk and watch the balance rather than individual
results. The long flat stretches are the game's normal condition, not bad luck.
Compare risk levels over the same number of drops. The difference in feel is large;
the difference in outcome over time is not.
Count how often the edges actually hit. Almost always fewer times than expected.
Where the demo misleads
Not in the maths — in the psychology. Losing imaginary money produces none of the pressure
that losing real money does, and the decision to stop is easy when nothing is lost by
continuing. Any confidence built in demo mode about how you will behave under pressure is
unearned.
A fair test. Give the demo a fixed starting balance equal to a real
session budget and stop when it runs out, rather than topping it up. That is closer to the
real thing than an unlimited balance.