Dig

Dig is a move used by Knuckles the Echidna, and later by Rouge the Bat, Tikal the Echidna and Chaos 0. It is a move where the user digs into the ground to find burried items. It first appeared in Sonic Adventure and Sonic Adventure DX, and later in Sonic Adventure 2 and Sonic Adventure 2: Battle. It serves as a primary game mechanic in the Action Stages where the player has to search for hidden objects.

Usage
When performing Dig, the user begins diggging into whatever surface that can be dug into, such as grass, soft dirt and stone, and then disappears into the said surface. After a short while, the user emerges and can sometimes bring burried objects with them back up, such as item boxes containing rings, extra lifes, different types of shields or even invincibility or Power Sneaker power-ups. Mostly however, the Dig move is primarily used to find the hidden Emerald Shards in each stage. This move can be performed while standing, climbing or gliding.

Sonic Adventure
The Dig's first appearance was in Sonic Adventure, where it was only used by Knuckles the Echidna. In order to perform Dig however, Knuckles had to have obtained the Shovel Claws upgrade.

This move was primarily used by Knuckles to dig up the Emerald Shards of the Master Emerald (which was shattered and scattered after Chaos was releashed) which he managed to locate underground, but he could also use it to find other items such as keys to the various Action Stages. To perform Dig, the player has to press the action button and jump button simustaniously.

Sonic Adventure 2
The Dig made its return in Sonic Adventure 2 where it was used by both Knuckles the Echidna and Rouge the Bat. In order for them to perform it, they must each possess a certain upgrade; Knuckles must once again obtain the Shovel Claws while Rouge must obtain the Pick Nails.

The mechanics behind the Dig is identical to those in Sonic Adventure. It also serves the same purpose by allowing the user to find Master Emerald Shards and other items hidden underground. However, in this game, it was posssible for the user to dig into the wall they were climbing on and could also find hidden rooms and passageways if they were digging the right place. To perform Dig, the player can select Dig in the action window or press the B button while in the air or climbing.

In the remake, Sonic Adventure 2: Battle, Tikal and Chaos 0 were included as additional character in the game's 2-player mode's Treasure Hunt Race. Due to this, both Tikal and Chaos can perform Dig by default to find hidden Master Emerald Shards, since they are not a part of the main game and therefore do not need an upgrade to perform Dig.

Sonic Generations
The Dig move also made a cameo in Sonic Generations in the mission "Knuckles: Buried Treasure" where Knuckles uses Dig to find the golden medals which Sonic locates.