A Terrain Monster is a type of Monster Card created by LHK. Their card frame is dual coloured with graphite on the left and green on the right, which is similar to that of grass and dirt. These cards are placed in the Extra Deck.
Most Terrain Monsters have a set of Terrain Materials, which are listed on the first line of the card's text. These are the materials used to perform the Summon of that monster.
Like other Extra Deck monsters, Terrain Monsters cannot exist in either the hand or the Main Deck (even with card effects). If a Terrain Monster would be moved to the hand or Main Deck, it is returned to the Extra Deck instead. If a card like " " or " " is applying, the Terrain Monster would be banished rather than returning to the Extra Deck.
- Main Article: Terrain Summon
A Terrain Summon is the act of Summoning a Terrain Monster from the Extra Deck using a Field Spell with additional monsters. During the Main Phase 1 or 2, the turn player can Terrain Summon a Terrain Monster from the Extra Deck by sending materials from their field to the Graveyard (at least 1 Field Spell and 1 or more monsters).
When a Terrain Summoned Terrain Monster is destroyed and sent to the Graveyard while the Field Spell used as Terrain Material is in the Graveyard, they activate that Field Spell from the Graveyard and force it to activate if possible.