Seats at the roulette table are for players only. Even if a nonplayer sits down when only one player is at the table, the dealer will ask the nonplayer to move.
Play begins after the dealer has cleared off all losing bets and paid all winners from the previous spin. Players are given time to put down bets by placing chips on the layout before the dealer starts the spin. After the spin has begun, players may keep betting until the ball is about to drop from the track at the top of the wheel down toward the numbered slots. Then the dealer will call, "No more bets."
The ball will bounce around, then finally settle in one slot. Next the dealer will place a marker on the layout on the corresponding number -- or on top of any chips that have been bet on that number. The dealer will then clear away all losing bets and pay off all those who have bet on the winning number or on combinations including the winning number. When all that is done, the dealer will lift the marker off the number on the layout, and betting may begin again.
Deciding how many chips to place where on the roulette table depends on what type of bet you want to make. In the next section, we'll review the difference between inside and outside bets, and some betting systems used by experienced players.