There are more than one type of transformation. All of them are listed below.

Saiyan - Super Saiyan

On this RPG a saiyan can go Super Saiyan, when he or she hits a Power Level of 5,  then they can go Super Saiyan 2 when he or she hits a Power Level of 10. Super Saiyan 3 can be reached when he or she hits a Power Level of 15. Last of all for the Super Saiyan, there is Super Saiyan 4, this can be reached when he or she has a power level of 20.  Each transformation will double the Saiyans stats.

Saiyan - Oozaru

To transform into a Oozaru, or a giant monkey, the saiyan must have two things. First they must the technique, Fake Moon Blast, and second of all they must have their tail intact.  The technique will not work if the Saiyan has had his or her tail cut off.  To use Fake Moon Blast, you must learn it from the elder of the planet you are on.  This will take up one turn and cannot ever be used before battle. This will double the Saiyans stats.

Growth

If you have a technique called GROWTH, you can use it and it will double your stats.  You may only use this once during a battle.

CHARACTERS ABLE TO USE GROWTH
Nameks
Majin Buu
Fat Buu
Super Buu
If you tink there are any other, ICQ me and tell me.

Changelings

For a changeling to change to its next form, you must reach a certain Power Level. This works exactly like the Super Saiyan Transformation. Then it will be added as one of the changelings special techniques.  When the changeling wants to use this technique in battle they must say transform and this will take up one turn.  There will be no transforming before battles unless otherwise said my the owner of this site. Each transformation will double the changelings stats.

FRIEZA = 4 transformations
KOOLA = 5 transformations
KING KOLD =  5 transformations