Whenever your Environment Collision Box (ECB) collides with a wall while you are in hitlag or hitstun with a sufficient amount of knockback¹
and your teching (
Passive ) flag is active, you will walltech². If you hold up during the first 10 frames or so of your
PassiveWall animation, you will transition into
PassiveWallJump, coll. “walljumptech“.³
It is possible to SDI into a wall and enter the teching animation, unlike with floors where this kind of SDI is not possible (“forbidden smash DI”).
The closer to the wall you are, the less SDI inputs you will need to collide with the wall. If the post-DI knockback angle of the hitbox that hit you moves you towards the wall (again, ¹ applies), teching is possible as well. Samus’ and Peach’s dsmashes are good examples.
¹80 knockback, about as much as Fox’s shine has on PAL Marth, which causes him to fall down – unless NTSC Marth, whose knockback is just below 80.
²There is no difference between a ledge tech and a wall tech. People call it ledge tech when it occurs on the part of the wall below the ledge, but it really is no different from a wall tech whatsoever.
³Possible with every character, regardless of whether he is able to walljump. See the second paragraph of this thread for an example of a useful application with Marth:
http://smashboards.com/threads/kadano’s-perfect-marth-class—advanced-frame-data-application.337035/
