A string is an attack with one or more built-in follow-up attacks. These are sometimes called extensions. In most cases these follow-ups are optional.
What a string is good for varies greatly based on what the follow-ups are. They may track people who sidestepped the original move, or not. They may counter hit people who blocked the original move and retaliated, or be gauranteed to hit when the original move hits, or none of these.
A string can even jail on block. This means if the original attack is blocked, so is the extension. This changes how the string can be used.
Examples:
- An opponent doing a DF1 is commonly -3 on block. But they have a string follow-up that can counterhit any attack you do, due to coming out faster than a normal attack. This is often a high or unsafe mid that also hits people trying to sidestep after the DF1 is blocked. If you visually confirm they haven't done the string extension before doing anything, you'll be acting at a delay.
- Most 1 jabs have a 2 string extension that adds damage, range and sometimes tracking, but is -1 on block. This string jails, so if the 1 jab is blocked, so is the 2. Because the 1 jab is i10 and the 2 is often i10 to i12 after this, this string will rarely be interrupted even on whiff. Hence, it can be used to control space, too.