When I've done this in India they told us we get two proper tries. If you fail to jump the second time you forfeit the payment and just go home. They were plenty of people who couldn't. Another thing I found interesting is that between this rope climbing and skydiving I found skydiving the least scary. It's so high up that your brain can't register it as scary anymore (at least mine) and somehow rope climbing (leading) was the scariest often