When Image Training, the fighter involved closes their eyes and pictures a foe, they then proceed to fight them as they would in a real battle. Two fighters can participate in image training together by linking their minds. Fighters can get stronger through image training.
Image Training is useful as it allows one to train practically anywhere thus it is useful when confined (such as Frieza while cocooned in Earth's Hell) or in an area that would prohibit a normal training regimen (such as the Nameless Namek's Spaceship).
In Dragon Ball Super, in the manga Goku undergoes image training in his radish field prior to Beerus' arrival. He faces final form Frieza and defeats him with one blow as a Super Saiyan. He then faces Perfect Cell and quickly defeats him. He prepares to face off against Kid Buu, but the training is interrupted before he can.
In both the manga and anime, after his death during his attempted revenge, Frieza underwent image training while in Earth's Hell, battling and killing Goku and the other Z Fighters thousands of times. Frieza's power and energy control increased greatly thanks to this.
In the anime, after returning to the present, Future Trunks underwent image training against Goku Black, but was unable to defeat him in any of the sessions. Shu demonstrates an awareness of image training giving a brief explanation of it to Mai as he and her observed Future Trunks' image training.
Video Game Appearances
Dragon Ball Z: Kakarot
"Piccolo... You came... I like to do a little image training every now and then to make sure I don't get too rusty... Time to see what I can do...and you're just the guy to help me do that!"
In Dragon Ball Z: Kakarot, the game opens with Gohan finding Goku as he is performing Image Training. During his Image Training, Piccolo appears and Goku notes he does image training every now and then to ensure he doesn't get too rusty and that Piccolo is the perfect opponent to test himself against. Goku then fights against Piccolo as part of his image training which acts as the game's battle mechanics tutorial where the objective is to defeat Piccolo.After defeating Piccolo, he attacks Goku with an Energy Wave which Goku counters with a Kamehameha resulting in a brief Energy Clash. However Goku is forced to end his training session as Gohan calls to him to tell him they'd better head home or they'll have to face his mother's wrath. Goku apologies for getting carried away in his image training.
- Stop the Saiyan Invasion Episode 1
- "A Long Overdue Reunion"
After receiving the Turtle School Training Manual from Master Roshi, Goku talks to Krillin. Krillin rejects Goku's offer to spar as he wants to focus on some Mental Simulation Training which is what Krillin calls Image Training in the game. Krillin gives Goku a D Medal which he can spend at Training Grounds to acquire Super Attacks via Mental Simulation Training.
- Evil Emperor Frieza Episode 1
- Training Sub Story - "Wild Imagination"
Gohan finds Krillin at Kame House looking at a Dirty magazine. Krillin quickly puts the magazine away and claims he's been during research on methods so they can train on the trip to Namek. He suggests they do mental simulation training though Gohan notes he's done that before. However Krillin says that he's discovered a method that allows two people to do mental simulation training together. Gohan wonders if it is even possible so Krillin suggests they try it out right now (meanwhile Krillin thinks to himself that Gohan actually bought it and says it's a good thing he came up with the idea beforehand allowing him to avoid Gohan finding out what he had been really been doing). This leads to the Sub Story "Wild Imagination".
During the Sub Story, Krillin and Gohan perform Mental Simulation Training together on the beach in preparation for their journey to Namek. Gohan has Krillin explain how two person Mental Simulation Training works. Krillin explains they first need to match ki levels and that Gohan should be able to handle that easily now. Gohan matches his ki level to Krillin's with no trouble. The next part if they need to picture each other in their heads as clearly as possible which is the most important thing as they must really focus. Gohan tries picturing Krillin in his mind starting with his shiny bald head though Gohan realizes other bald people have shiny heads too and ends up imagining Nappa. Krillin asks what Gohan is picturing and Gohan apologizes for kind of getting distracted though Krillin notes he's beyond distracted. Gohan says he got it right the first time. Krillin suggests that since he was able to form a mental image he should try and fight it. This leads to Gohan fighting Nappa's image.
Gohan defeats the image of Nappa and Krillin says he can't believe Gohan thought of that Saiyan instead of him. Gohan apologizes and says he couldn't help it. Krillin asks why Gohan had to focus on Krillin bring bald. Gohan says it's the first thing that comes to mind when he thinks of him. Krillin thinks to himself that Tien's bald too before sighing to himself. Krillin tells Gohan to try again and imagine him this time. Gohan does so and after focusing he manages to see a mental image of Krillin. Krillin is happy with Gohan's success and suggests they go another round as the more they fight in their minds the more their minds will get used to this form of mental training. Gohan and Krillin imagine themselves sparring in the sky above Kame House and Gohan defeats the image of Krillin. Krillin asks Gohan if he thinks they'll be able to do it on the close quarters of the spaceship. Gohan thinks they do as while they don't have the room to move around much on the ship l, but in their minds they'll have plenty of room. Gohan asks to practice one more time so he can make sure he has the technique down. Krillin says they can do it as many times as they want. Krillin thinks to himself that Gohan's got Chi-Chi to thank for his maturity as the kid is definitely not like Goku and decides to go back to his magazine after he's done mental sparring with Gohan. Krillin notes he shouldn't be thinking about that now and focuses on picturing Gohan in his mind. Unfortunately Krillin loses focus and starts thinking about his magazine causing him to imagine a hot babe with purple hair wearing a red bikini. Gohan is confused as to why he's looking at a girl and Krillin lies by claiming it's an image from Master Roshi butting its way into his mind and says their no helping that old-timer. However Gohan notes Master Roshi is nowhere near them and Krillin continues his lie by saying that Master Roshi is so good at mental image training that he can project his image really far. However Gohan see through his lie and Krillin is forced to come clean and Gohan realizes he was looking a Dirty magazine. Krillin says Gohan is seeing a side of him that he was hoping he'd never see. Gohan says he doesn't need to hide things from him though Krillin worries he lost some respect for him and he was hoping to maintain his cool mentor image for Gohan. Gohan thinks to himself that he views Krillin more as Goofy and strong and not really as a cool mentor. After this the Sub Story ends with Gohan having learned the basics of Mental Image Training with another person.
- Training Grounds
As a character levels up and acquires skills through the Super Attack Skill Tree, Mental Simulation Training exercises to unlock certain Super Attacks become available. During these exercises the character will face off against images of other characters and defeating them will unlock the Super Attack for that particular exercise. To perform Mental Simulation Training, one must go to a Training Ground which appears as a blue column of light (they are represented by a flexing muscle icon on the Area and Mini Maps). Exercises often have unlock requirements such as leveling up a particular Super Attack on the Skill Tree. Additionally each exercise costs a certain number of D Medals. Training at Training Grounds is optional but is required to obtain certain Super Attacks such as Goku's Super Kamehameha, Limitbreaker Kamehameha, and Guided Kamehameha, Gohan's Super Masenko, Vegeta's Super Galick Gun, and Piccolo's Super Special Beam Cannon. Each exercise also features a Recommended Lvl though this is just a suggestion and not a requirement. The images of enemies fought during these exercises are depicted as blue and translucent, while those fought during the Mental Simulation Training sessions in the main story and Sub Stories are depicted as solid and completely identical to the character they represent.
- In Kakarot, it is established that after marrying Chi-Chi and fathering Gohan, that Goku would perform image training every now and then to ensure he doesn't get rusty. This fits with his use of image training during the God of Destruction Beerus Saga in Dragon Ball Super.
- In Kakarot, Krillin explains how two-person Mental Simulation Training works to Gohan before the trip to Namek. According to him, the pair must match their Ki levels and then focus on creating a mental image of the person they wish to spar with. Both participants must focus properly to create the proper image as losing focus can cause them to produce the wrong image (as shown by Gohan creating an image of Nappa due to getting distracted while trying to imagine Krillin by focusing on his bald head and by Krillin creating an image of a hot babe due to thinking about the Dirty magazine he had been reading).
- In the case of Gohan accidentally creating an image of Nappa, Krillin had him fight against the image before attempting to create another image Krillin. Presumably, this was to help Gohan clear the image from his mind by defeating it (which likely helped Gohan get over some of the trauma left behind from his battle with Nappa and survivor's guilt from Piccolo's death which Gohan was unable to prevent due to lacking the strength to defeat Nappa).
- In the case of Krillin accidentally creating an image of a hot babe, demonstrates that perverted or impure thoughts can cause one to lose focus and create an image that is unsuitable for training.
- This leads to a suggestion that image training possibly having "other uses" outside of martial arts training. This makes sense as mental images are produced by the user's imagination.
- Any image created as a result of losing focus can be seen by the person who's mind they are linked with as Krillin saw Nappa after Gohan imagined him and Gohan saw the hot babe after Krillin imagined her. This can lead to embarrassment depending upon the nature of the image created as a result of losing focus (Krillin was forced to come clean about what caused him to imagine the hot babe, though Gohan noted it didn't make him think any less of Krillin as he already saw him as goofy yet strong martial artist anyways as it was just another example of his goofiness to mess up like that).