Ki 

Ki Attacks

A ki attack is an energy beam, or ball, which is made by the attacker. The different attacks require different techniques to do. Most of them require great concentration, and arm movements which are very complicated. Different warriors tend to have their own signature attacks, such as the KameHameHa, Kaio-kan, Spirit Bomb, Masenko, etc. The attacks can be used in battle, or be used to boost yourself up as you fall to the ground, should that scenario ever arise. ki can be used to dry off clothes, light fires, emit heat, and other things along those lines. To use a ki attack, you first must gather energy, and the more powerful you are, the faster you can do it.

Sensing Ki

Some people can sense ki without the use of any high-tech equipment. They close their eyes, look in the general direction of the power that they hope to sense, and try their best to feel it out. To sense the power, they must be searching for the approximate range that the power would go in, because if they search too high for example, they wouldn't be able to sense people with low power levels, such as people near to death. This is the primary requisite of many warriors, as they can sense how strong their opponents are. The problem with this is that you can't get the exact power, but can usually tell whether it is stronger, or weaker than your own though. The advantage is that it doesn't cost anything, unlike the expensive scouters. Using this method, they can dodge enemy attacks by sensing for their ki. All of the human Z fighterscan use this skill, as can Vegeta, as he learned it from them. Most of the "evil" people are unable to use this ability though, because no one has taught it them, or they haven't picked up on it.

Scouters

This is another of reading ki levels. The scouter can measure the exact power level of anyone. All you have to do is focus it onto someone, and press a few buttons. It gives you a read out of the power level, and any special skills that this species of creature may have. The scouters fit like an earpiece, and go over the eye. Most have a type of green glass display screen. If it reads a power level that is either increasing faster than it can handle, or is too large for it to handle, then it makes a small explosion, causing the wearer to have to take it off, suffering no harm. Scouters are expensive though, and there is a fairly limited supply, meaning that once they get destroyed, it can be hard to get hold of another one immediately. Another function of the scouter is as a communication device. People can talk into them, transmitting their voice to others, even if they are on the other side of the galaxy. Scouters are probably better than using your senses.

Hiding ki

A select group of people are able to hide their ki, so it seems that they are a lot less powerful than they really are. This is a skill that the Earthling Z fighters really excel in. it can be useful for throwing enemies off, and making them underestimate you. Vegeta has managed to master this, along with the Earthlings, as he has been a witness of them doing this, and managed to pick up on it. This technique has been utilized many times, and has fooled even the most intelligent enemies.