On this page of the Tunic guide, you will learn how to get Dash. It is a magic skill in the game that will allow you to teleport a short distance (improved roll).
To find Dash, you have to obtain the sword, shield, lantern, wand, and a magic ball first. The way to get them all is described on the pages: Sword - how to find?, Shield - how to find?, Lantern - how to find?, Wand - how to find?, and Magic ball - how to find?.
You can get Dash only at the end of the game (after the first encounter with the final boss - The Heir) and only when the physical form of the fox turns into a ghost of the fox. So if you're not in a ghost form yet, don't worry - it's not time to obtain the dash skill.
But, if you are at the right moment in the playthrough, go to the Swamp Old Burying Ground located south of Overworld and east of The Ruined Atoll through the destroyed bridge near the game's starting location.
At the very beginning of the location, you will find a shrine (checkpoint) - interact with it, and then go north. On your way, you will encounter Lost Echo, an invisible opponent. Once you deal with it, you can go upstairs to the cemetery. Try to avoid the Fleemers and Hushers hidden there, using the side path. Finally, you will reach the closed door of The Cathedral, which you will open by interacting with a nearby cuboid.
Once inside, you will get to a room with enemies and a hidden elevator that you can activate using the obelisk. How to get to it? In the small square room complex, turn right twice and then left once. You will encounter mirror images of the fox that you have to defeat. Eventually, you'll end up in the room with the purple liquid - stay close to the wall, go up the stairs until you reach the room with the spikes. Then you will have to go up the stairs and through a narrow corridor with birds - so just sprint ahead because fighting in such a place does not make much sense. After a while, you will find a ladder that will be a shortcut to the first room in the Cathedral (the one with the elevator and chapel).
After unlocking the shortcut, go back to the corridor with birds and follow the linear path. On your way, you will encounter two dangerous mirror images of the fox and find a room with statues firing lasers. After destroying them, you will enter a large room with a mysterious creature standing in the middle. It is facing the obelisk with which you have to interact to activate the elevator mentioned earlier. Now, you can use the elevator.
Once you get down, you'll reach an arena - you'll have to face several waves of enemies. We are talking about frogs, Rudelings, Fairies, Custodians and two Garden Knights. Remember that between the waves, you can use the shrine in the arena, and you will get a lot of healing hearts. After the battles are over, you will be able to claim your reward, which is Dash.