Taking risks has been part of our daily life since the early evolutionary times. Back than without risk there was no survival or reproduction. Risk-taking lead mankind to our sophisticated society we live now. These days behind risk taking besides survival and reproduction there is money, love and power.
Risk-taking is a very positive behavior if it's used properly. Without risk life would be very boring, everything would be predictable. When we talk about risk we always imply that there is a possibility of danger, tension and loss.
Each risk has two sides, an upside and downside. If the downside is much higher than the upside the risk is considered a "stupid" risk. Why would you spend your paycheck on lottery tickets? You could lose everything and win nothing.
Calculated risk or intelligent risk is when the downside or loss is limited and the reward far outweighs the downside. When you apply for a job there is risk, you might be rejected but on the upside you could land in a great carrier. When you try to date someone you could also be rejected but you could also find some who will be with you for the rest of your life. When you start a business there is risk, with unlimited potentials on the upside.
People, businesses, governments take risks all the time. We do things all the time where we are not sure about the outcome. Risk with a limited downside is always welcome but unlimited downside or "gambling" can turn against us.