From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Scouters (スカウター, Sukautā; FUNimation "Scouter") are devices that read battle powers and other information.
The Scouter's primary purpose was to calculate the individual battle power or ki concentration of biological characters by converting the readings into numbers. It was never explained what units of measure were used to read Ki levels. Akira Toriyama simply stated in an interview that it could not be done by conventional means.
Scouters also served the purpose of gathering information about soldiers wearing it and for interstellar communication, as seen between Raditz and Vegeta. They could also tell the location and battle power of an individual, as demonstrated when members of Freeza's Force used Scouters to hunt down enemies.
The Scouter appeared as a semi-transparent colored monocle that covered the left eye. The first Scouter to be seen was the one Raditz wore in the first episode of Dragon Ball Z upon his arrival on Planet Earth. The battle power was given as a number without any units of measurement (5 for the Farmer, 334 for Son Goku before he took his heavy clothes off, etc).
It is unknown what the color of the Scouter means. The most frequently seen color was green, which is suggested to be a standard model, while alternate colors such as blue, red, and purple are suggested to be upgraded models. Zarbon's blue Scouter, however, broke after escalating to a reading of 22,000, while Dodoria's green Scouter was suggested to be newer as it read a battle power level of 24,000 without exploding. It is possible that the colors may be attributed to the capacity of power each can read. It is also a possibility that the colors serve merely as an aesthetic.
Though it is possible to sense others' ki without advanced machinery, as the Z Warriors do, Scouters provide the ability to read power levels to less-trained fighters. Scouters do have some disadvantages, however. Their main drawback is that a trained person is capable of consciously lowering their ki (see Power Up), and can therefore fool Scouter users into thinking they have a lower batlle power. Nappa says he believed that was how Raditz had been killed.
Another disadvantage is that Scouters may explode on certain conditions. The reason for this is not mentioned explicitly in the anime or the manga, but the recorded cases have happened when the Scouter is detecting a high battle power level, possibly overloading it. Dodoria suggested that it was a problem with older scouter models. Older models (such as Raditz's and Zarbon's) seem to explode when reading levels between 21,000 and 22,000. Newer models (such as Dodoria's and the ones used by the Ginyu Special Corps) can read higher power levels without problems, at least up to 180,000, though their limits are not known. According to Daizenshuu 7, there are only two generations of scouters. The first generation ones explode when reading a power level over 22,000, something that is corrected in the improved second generation scouters.
It is also possible for scouters to give inaccurate readings, since Raditz believed his to be giving incorrect signals and going haywire when it read Gohan's power level at 710 (in that case, the reading was accurate).
Scouters were suggested to have originally been invented by the Tuffles, according to the anime, until the Saiyans exterminated them and stole their technology. From the Saiyans, scouters were introduced to Freeza's forces, and during the series, almost all of Freeza's soldiers can be seen wearing one. It may be possible that the scouters were designed by Freeza's Force, if the anime is not taken into account.
In the series, the Scouters are used from the beginning of Dragon Ball Z up to the arrival of Future Trunks during the Trunks Saga. After the fighters learned to manipulate their Ki output and sense other beings' Ki concentration on their own, Scouters became totally useless in the series. Both the first and last power level read in the series was five; the first power level read was a farmer with a shotgun, and the last was Trunks' suppressed Ki level. The highest power level read in the series was Goku's, during the Captain Ginyu Saga, that was recorded to be over 180,000, while powering up the Kaio-ken.
The Scouter used by Raditz has the distinction of being the very first scouter to appear in the series. It actually plays an important role, as it transmits information regarding the Dragon Balls back to Vegeta and Nappa (as well as the fact that Raditz had been killed), setting in motion the events that lead to Goku's confrontation with Prince Vegeta.
After Raditz was defeated, Bulma Brief took possession of his scouter. Though it had been damaged slightly, it took her a single night to repair it. She even managed to switch it over to Earth's numeric system. She tested it out on Master Roshi and Krillin (she also tested it on Turtle in the anime), and they used it to locate Yamcha and Tien. The scouter remained in Bulma's possession up to Goku's fight with Vegeta. It was the first scouter to blow up, as it was reading Goku's power level, which was rising too fast due to Goku's using the three-fold Kaio-ken in order to match Vegeta. It is unknown if Bulma kept the surviving piece or if she ever repaired it, however, this is unlikely, as it is never seen again.
After the arrival of Trunks, Androids 16, 19, and 20 can be observed to possess a device that calculates and locates power levels like scouters once did. (These devices also had the merit of not malfunctioning when an enormous power was detected.) However, it is unknown whether or not they calculate power levels with the same units of measure (they probably use an Earth-based numeric system).
During the World Tournament Saga, the World Martial Arts Tournament had developed a punching machine that would measure the strength of the fighters' punches (apparently in units of force) to replace the preliminaries in order to reduce injuries; this machine served the same purpose that a scouter would serve if they were used by the Tournament. It is also worth noting that Mr. Satan scored 137 on this machine, further emphasizing the fact that he is a genuinely skilled martial artist when not compared to the Z-Fighters, since, if the units were the same used by scouters, he would be only two points below Master Roshi in his prime.
During the Majin Buu Saga, the wizard Babidi can be seen to have a device that calculates kili levels. However, the units of measure are much larger, being that Full Power Super Saiyan Goku's level was calculated to be around 3,000 kilis (and 300 killis was enough to destroy a planet). The device was also used to measure the unusual power of Super Saiyan 2 Gohan at the World Tournament when he powered up in front of Kibito, though his power level was never stated.
Akira Toriyama based the design of Saiyan scouters on Mitsuteru Yokoyama's 1956 manga Tetsujin 28-go. An antagonist character named Alberto had lost his right eye, and was wearing a metal patch that somewhat resembles the scouter in appearance, and also acted like a tracking and communication device.
A device similar in design to the scouter also appears in the Blue Dragon series, whose characters were also designed by Toriyama.
Scouters often appear in Dragon Ball Z video games. In many ways, scouters could be considered a signature part of Dragon Ball Z, hence their constant presence in Dragon Ball Z video games and other media.
In fighting games, they often appear on-screen representing a health or energy bar. This trend can be seen in both Dragon Ball Z: Budokai and Dragon Ball Z: Supersonic Warriors. Also, in Super Sonic Warriors after the end of fight, a scouter is used to calculate the player's score. In Budokai 3, in the game's story mode, scouters are used by characters like Prince Vegeta. In the Budokai Tenkaichi series, some characters (like Bardock, Raditz and Nappa) have a special type of lock-on they can use to detect an opponent even if they are hidden behind an object. If the user receives too much damage, however, their Scouter is destroyed and their lock-on suffers as a result. (This is similar to what is seen in the manga and anime.)
In Dragon Ball Z: Sagas, the Scouter is used to represent the game's menu screens and interestingly it shows the fake battle power of all the game's boss characters before they are fought (even characters like Freeza and Cell).
In Dragon Ball Z: The Legacy of Goku II (which is set after the Garlic Junior Saga), a Scouter can be obtained from Bulma after getting the electronic parts she needs to build it (a Scouter model created by her, likely based on the Scouter she obtained from Raditz's body, although dialogue states she found it on Planet Namek.) Once obtained, her Scouter can be used for the rest of the game. Bulma's Scouter can be used to scan enemies, allies, neutral characters, and animals. The Scouter will give information about any character scanned by it (hit points, height and weight and character scan-bio). It also has a handy map feature, and at the near the end of the game, it can be upgraded (by Bulma) to work as a Dragon Radar. Also, all of the Scouter's scanned information can be transferred and stored on a computer inside the Capsule Corporation. This computer can be used to view information on any character that has been previously scanned. Bulma's Scouter reappears in the follow-up game Dragon Ball Z: Buu's Fury where it is available at the start of the game.
In Dragon Ball Z: Attack of the Saiyans, a Scouter is obtained after Raditz is defeated and Bulma repairs the Scouter. It shows the battle power, the items dropped, the strengths and weaknesses, and the experience obtained from an opponent.
In Dragon Ball Online, a video of the game's opening character select screen shows Humans, Namekians, and Majins wearing Scouters.
- Bulma is the only good character to use a Scouter in the manga canon. Tarble also wears one until it is blown up by Son Goku's power. Vegeta is also the only one of the Z Warriors to have ever used a Scouter.
- In the video game series WWE SmackDown! vs Raw, SvR 2006, 2007, 2008, and 2009, there is a headwear piece that closely resembles a Scouter to be found in the Create-A-Superstar character creation mode.
- In the MMORPG game Maplestory, players can purchase an item called a Scouter in the special store. It is an eyewear equipment item, but is just for looks. The eyepiece of the Scouter is pink.
- The first and last battle power read by a Scouter in the series is '5'. First from a Farmer by Raditz and then Future Trunks' suppressed battle power by one of Freeza's henchmen. This is the last time a Scouter is seen in the main series.
- Star Fox characters Fox McCloud, Falco Lombardi, and Wolf O'Donnell occasionally wear devices that appear similar to Scouters.
- The website Gaiaonline has an item that resembles a Scouter, though it is only an item to be equipped to your avatar.
- In "Go, God Go", an episode from South Park, Otter army members are seen wearing Scouters.
- Scouters gave rise to one of the most popular Internet memes, It's Over 9000!
- In the Bridge Entertainment version of Dragon Ball Z: The Tree of Might, Tullece refers to his Scouter as a "portable computer".
- In the online game Lost Saga, an Epic gear looks like a Scouter
- In the game Scribblenauts, if a player types "It's Over 9000", a Scouter-like object will appear and can be worn on Maxwell's eye. It has no other purpose.
- There is a show named The Amazing Spiez where there are four kids working under Jerry's WOOHP wearing a green device which is similar to a Scouter.
- The anime and manga series Yu Yu Hakusho has devices similar to Scouters, but they are handheld. They are used by the demons that serve Yomi and were used to measure the power levels for the 5 demons Jin, Chu, Rinku, Suzuki, and Shishiwakamaru when they arrived at Yomi's palace. It is also used to read the power level for Kurama/Yoko Kurama as well as that of Yomi's clone, Shura, during his growth development and Yusuke when arriving at Yomi's palace. Yomi's computers also read the power levels for the Makai Generals, the Three Kings of the Makai (Demon Realm), and for Raizen's friends.
- The Facebook game Ninja Trick has an item which strongly resembles a Scouter. It is called the Galaxy Scanner and has an green eye part.
- In the online game Wonderking, there is an accessory called the Scouter with a red eyepiece and a description saying "It's over 9000".
- There is a Scouter app for modern-day smart phones that when pointed at a person will calculate their battle power. The generated number is most likely random.