A tech is an action performed when the character hits the ground, a wall, or a ceiling while tumbling or in hitstun. To tech, the user must press L or R 20 frames or fewer before hitting the surface, after that, a player won't be able to tech for 40 frames; other button or control stick input can cause different types of techs.
Types of Techs
A standing tech is a neutral, ground-based tech performed by pressing L or R when a character comes in contact with the floor. The character will experience a brief period of invincibility, and will quickly bounce from the ground into a standing animation.
A rolling tech is a ground-based tech performed by tilting the control stick left or right on the control stick when teching. The character will bounce from the ground into a roll-like animation during which the character moves left or right while invincible.
A wall tech is a tech against a wall. The character immediately loses his knockback momentum and starts a neutral falling animation.
A wall tech jump is a wall tech performed by pressing X, Y or up when teching. The character will jump, à la wall jumping. Though wall jumping is restricted to eight characters, anybody can wall tech jump.
A ceiling tech is a tech against a ceiling. As with the wall tech, the character loses his knockback momentum and starts a neutral falling animation.
Tech Use
Teching can be a lifesaver in many situations and is a good technique for beginners to learn and practice.
Occasionally after accumulating sufficient damage, one will experience a wall or ceiling rebound that will send the player plummeting off-stage. This can be prevented by applying a wall or ceiling tech, saving the player from a deadly ricochet. This is especially useful in Hyrule Temple: a character in the large lower section of the stage can survive to very high damage and can immediately retaliate from otherwise-deadly blows. This unusual longevity is one reason Temple is banned from tournaments.
The standing and rolling techs can be performed in many more situations, and can allow a character to avoid continued assault after being knocked back. However, in many situations an opponent can predict a player's teching patterns and hit him again after knocking him down; knowingly setting up such situations is known as tech chasing.