Base Clipping A Block

We've looked at multiple ways to clip a block--from its left or right with a regular corner clip, and nearly from the top with a corner clip without max speed.  However, what if you wanted to clip a block from its base (bottom of the block)?

Well, there are multiple ways to do the clip through the bottom, and most of them are relatively easy.

Method 1 - Sprite Boost Methods

There are lots of sprites in the game that when you are on top of them, you will not take damage so that you can stand on them, but yet your collision check with ceilings is ignored since you are going downwards, even if that downwards is on a sprite pushing you upwards.  This allows us to, if we stand on a sprite moving upwards, completely bypass the ceiling check.  Many items when manipulated can be used to perform this:
1. When you start jumping, there is a frame that, when you throw a springboard upwards, it will briefly be under mario.  If you hit a ceiling during this, mario will land on the springboard, but the spring will still be going upwards.
2. If you throw an item that you can stand on shortly after jumping off of a springboard, you will be able to stand on it when it is moving upwards.
3. The speed achieved when jumping off of yoshi on the first frame that you land on him is enough to land on an item that you have just thrown into the air.

Method 2 - Yoshi with Collision Interruption

Yoshi is very special when it comes to base clips (and every other clip? :P).  With yoshi, if you manage to get on him, but he is in the ceiling, if you boost off of a sprite on that frame (or frames), you will be enough inside the block in order to jump right through it.  Boosting just by jumping on a p-switch, spring, or key will allow you to do this.  If you mount yoshi in a one-tile vertical space, the boost off of a shell on the same frame you are in the ceiling will achieve the same thing.  However, this trick is a lot more precise with a shell, as it depends on where yoshi is when you mount him, and the invulnerability frames of the shell at the same time.

Method 3 - Getting Boosted from Two Sprites While Big

If you have ever put two items together against a wall, and been in between the wall and the two sprites, you will notice that the two sprites act as a solid block.  The same works in the vertical direction, just a lot more precise.  Throwing two items so that they will just land in the correct position (todo: find that position in relation to the block) on the ceiling of the block, and landing on them on that frame that they are just by the ceiling, will allow you to be far enough up into a block in order to jump through it.  This can be done with two keys, two p-switches, and should not be possible with a spring, since springs take a little time to even boost you.

Method 4 - Boosting Directly Off Of Yoshi

If you are big, and mount yoshi in the ceiling, the frame that you are in the ceiling, if you jump off of yoshi, you can jump through the ceiling.  This can only be done as small mario only if yoshi was originally mounted at a high point in the ceiling, making this trick very conditional.