Leg-spinners bowl the ball far slower than pace bowlers (approximately 80-90 kilometres per hour rather than the 140-odd km/h of good quality pace bowlers), and typically use variations of flight by sometimes looping the ball in the air somewhat, allowing the effects of any cross-breeze and the aerodynamic effects of the spinning ball to cause the ball to dip and drift before bouncing and spinning (usually called "turning") sharply. While very difficult to bowl accurately, it is the most effective form of spin bowling against right-handed batters as the spin takes the ball away from the batter rather than in towards them, which is much more difficult to deal with.
Good leg spin bowlers are also able to bowl deliveries that behave unexpectedly, including the googly, which turns the opposite way to a normal legspinner, and the topspinner, which doesn't deviate significantly. A few exceptional legspinners (notably Shane Warne) also mastered the flipper, a delivery that like a topspinner goes straight on landing but travels quickly and barely bounces on landing, often dismissing batters leg before wicket or bowled.
In the 1970s and 1980s, it was feared that leg spin would disappear from the game with the success of Australian and later West Indian teams exclusively using fast bowlers. However, leg spin has again become popular with cricket fans and a successful part of cricket teams, as the contest between batter and bowler is perhaps more cerebral than the physical contest between batters and faster bowlers.