Mossdeep city is a small island in the north-east of the region. This island is the home to Steven Stone and the Space Centre where you can learn of various space launches.

e-House
In the city in Ruby & Sapphire, there is a house where the backroom is blocked by boxes. This house opens up when you scan in various trainers using e-Cards on the e-Reader. These trainers are then battleable constantly from there.

Game Corner
In Emerald, there is a house where you can play one of two mini-games using the Wireless Adaptor; Pokémon Jump and Dodrio Berry Picking

Move Tutor
In the shallow waters at the bottom of the island, there is a Black Belt who will teach your Pokémon Dynamicpunch. This costs nothing but can only be taught once

Name	Type	Cat.	PP	Att.	Acc.	Effect
Dynamicpunch			5	100	50	The user punches the target with full, concentrated power. It confuses the target if it hits.

Gym
In Ruby & Sapphire, the Mossdeep City Gym features a sliding tile puzzle where you get sent around the gym and put in front of trainers. Dotted around the gym, you will find switches which open the path up. In Emerald, the gym runs off of a puzzle where you have to use switches to rotate statues around to create paths. At the end of the Gym, you will encounter Tate & Liza, the Psychic-type leaders and the first Leaders fought in a double battle. Defeat them and you will earn the Mind Badge and TM04, Calm Mind

Special Moves used in Mossdeep City:
Surf