Increment time controls are already the FIDE standard in Europe, and are likely to take off here in the states. The Miami International which takes place next month with a 100K prize fund appears to be the first major event stateside to use this. From running a few invitational events, it is apparent that there is some confusion as to rules with increments, so I thought I would address it.
First, what is increment, and why is it different from time delay? With time delay, simply the clock does not start ticking until the delay time (usually 5 seconds) has run out. With increments, you get a "bonus" amount of time added to your clock after you complete a move. Adding to the confusion, increment time controls are also called bonus, accumulating, Fischer, and there may be a couple others.
Are there different rules for this? Yes, the most notable rule is that regardless of the time left on a players clock, they must keep notating. As a TD and organizer, I love this, because complete gamescores are more common. As a player, the main difference is the feeling in time trouble. With regular delay controls, the pressure is constant. Such as, I have 30 seconds left on my clock, I must move quickly. During time pressure with an increment control, it comes and goes, and is easy to let your guard down. You may have 30 seconds, make 3-4 quick moves and be back over 2 minutes and start to relax. It is difficult to get used to.
Which clocks are capable of increment settings? Most recently manufactured European made clocks have it, and it is easy to find. But here, the two most common types of clocks, the Chronos and the Excalibur Game Time 2 both have it, though it is difficult to find and most players don't know it is there.
For the Chronos Blitz, it is right in the standard options. For the regular larger Chronos, you must go into the programming menu to the ChP5 setting and set the time control, and then scroll to where the delay would normally be set and set the increment. For the Excalibur, when you are in the programming menu, turn off the time delay, and turn on the Accum, set the Accum to the desired increment, and you are ready to go.