The word that confuses most people claiming a no deposit bonus South Africa offer is wagering, and I think it confuses them because nobody ever shows the math with real numbers. So let me do that, because once you see it with actual rand, the whole thing stops being mysterious.
Say a site gives you 20 rand as a no deposit bonus with 40x wagering. That 40x means you must stake, in total, 40 times the bonus before you can withdraw anything. Twenty rand times 40 is 800 rand of total stakes. Not deposited, staked. You put 800 rand through the games, usually slots, and only then does the balance become withdrawable.
People balk at this, and they should. Eight hundred rand of staking for a 20-rand bonus sounds steep, and it is. That's exactly why the wagering multiple matters more than the headline number. A 20-rand bonus at 40x asks less of you than a 50-rand bonus at 60x, even though the second one looks more generous on the banner.
The other numbers in the math
Wagering doesn't work alone. Game weighting changes what each stake is worth toward that 800. Slots usually count 100 percent, so a 1-rand slot spin moves you 1 rand closer. Tables might count 10 percent, so a 1-rand bet there only counts as 10 cents, meaning you'd need ten times as much staking to clear on tables. Clear on slots, or the 800 becomes 8,000 in effect.
Then there's the max cashout, the ceiling on what you can keep no matter how high the balance climbs. If that cap is 500 rand, the 800 of staking is buying you a shot at keeping up to 500. Worth it, maybe. If the cap were 100, that same grind buys far less, and the offer reads very differently once you put the two numbers next to each other.
So the full picture on that example is: stake 800 rand on slots, inside the expiry window, at or below the max stake per spin, to unlock a balance you can withdraw up to a 500-rand cap. Every one of those numbers is in the terms. The headline just shows you the 20.
Work the math once, on any offer, and the mystery goes away. You stop reacting to the big friendly number and start asking the only question that matters: how much do I actually have to stake, on what games, to keep how much. That's wagering, in plain rand, and it's the whole game.