Spin bowling.

Spin bowlers adopt similar sorts of tactics to fast bowlers, but with a different variety of balls in their arsenal.

Spin bowlers will have a stock ball that makes up most of their deliveries. For an off spinner this is usually the off break, for a leg spinner it is usually the leg break. They will bowl this ball repeatedly, with slight variations in flight, line, and length, to get the batsman into a rhythm, and then break it up with a variation such as an arm ball for an off spinner, or a googly or flipper for a leg spinner. If the batsman does not pick the variation, the different spin and bounce of the ball can cause him to miss it entirely, possibly getting him out bowled or LBW, or to hit it with the edge of the bat and produce a catch for close fielders such as silly mid off or shortleg.

Good spin bowlers can be dangerorus to bat defensively against, as they will usually have support with close fielders in positions to catch the ball if it flies in the air even a few metres from the bat. The variation in spin and bounce a spinner gets can cause this to happen off defensive shots even if the bat is angled to hit the ball straight into the pitch, because if the ball moves and catches the edge of the bat, the batsman's gloves, or comes off the bat into the batsman's leg pads, it can fly to a close catcher.

Spinners pitch the ball closer to the batsman that fast bowlers, because:

they have less speed on the ball, so they don't need to pitch as short to gain significant bounce by the time the ball reaches the batsman;
it gives the ball more time in the air before bouncing to drift;
it gives the batsman less time to react after the ball bounces;
there are often scuff marks on the pitch close to the batsman caused by the bowlers at the other end following through their run ups - this provides variable bounce and spin if they can pitch the ball in the scuff marks.

There are some options for spinners to get batsmen out that are not available to fast bowlers. Firstly, a spinner may tempt the batsman to come on to the front foot and then advance down the pitch by pitching balls successively shorter. If the batsman becomes confident in his ability to hit the ball, he may step out of his crease in order to get near the pitch of the ball and hit it for runs. At this point, a variation ball that does something unexpcted can get past the batsman and through to the wicket-keeper. Since the wicket-keeper stands right behind the wicket for a spin bowler, he can catch the ball and stump the batsman out if the batsman is too slow to return to his ground. This can also happen if the batsman simply misjudges a ball and misses it while out of his crease.

If the bowler has a ball that spins a long way from leg to off for a particular batsman (this may vary depending on the handedness of the batsman), he can sometimes pitch a ball far enough outside the leg stump that it passes behind the batsman's legs, but spins back far enough that it hits the wicket. This happens only rarely, and some batsmen will simply leave the ball, assuming it can't spin far enough to hit the wicket, while some may try to play at it but miss.
Bowling Over or Around the Wicket
Bowlers may choose freely whether to bowl over the wicket or around the wicket. They usually choose to bowl over the wicket, as this means their bowling arm is close to the middle of the pitch.

Bowlers will only switch to around the wicket for particular tactical reasons. These may include:

Changing the angle of attack to provide variation to a batsman who has settled in and looks difficult to get out.
Changing the angle of attack to produce a line that is either angled more in towards the batsman or across him and away to the off side. This can be done to batsmen known to be weak to one of these approaches.
A spin bowler changing his angle to allow a better chance of hitting scuff marks at the striker's end of the pitch.