They work quite similarly to Dark Synchro Summons, by taking the Levels of the Tuner monsters and non-Tuner monsters involved to summon an appropriate Extract Monster based on the difference between their combined Levels (OR subtracting the lowest value from the highest). However, there are a few key differences between them and Dark Synchro Monsters, their Tuner monsters don't necessarily need to be DARK monsters nor do their Levels need to be higher than the non-Tuner monsters.
When conducting an Extract Summon, you combine the Levels of the respective Tuners and non-Tuner monsters being used. Then you calculate the difference between the two values and Extract Summon an Extract Monster from your Extra Deck with the same Level, e.g. (1 + 1 = Level 6) - (1 + 1 = Level 2) = 1 Level 4 Extract Monster.
Unless stated otherwise, you can use any number of Tuners and non-Tuner monsters in an Extract Summon, but you must have at least one of each.
Extract Monsters are placed in the Extra Deck and count towards the fifteen card limit.
Extract Monsters are coloured grey, not be confused with Token Monsters.
- Toon, Spirit, Union, Gemini and Tuner monsters are overall treated as "Category" monsters, e.g. a monster who is a "[Machine/Union]" monster is a Category monster. However, a monster who is a "[Machine/Effect]" or just a "[Machine]" monster is not a Category monster.
- An Extract Summon is typically between 1 or more Category monsters and 1 or more non-Category monsters, e.g. "1 Category - 1 non-Category monster", but there are other more specific conditions, e.g. "1 Union - 1 non-Category monster".
- When conducting an Extract Summon, you calculate the Level difference between the Category and non-Category monsters involved and Extract Summon an Extract monster whose Level is equal to the difference.