Acrobatics

Acrobatics is a skill that allows Graceful Roll, as well as combat damage negation with the passive skill "Dodge".

Experience Gain
Experience in Acrobatics is gained by taking fall damage, successfully rolling on the ground, or successfully dodging attacks.

120XP per half heart of damage is gained when taking fall damage. Assuming no damage is being reduced, it can also be calculated as (b - 3) * 120 where b is the amount of blocks fallen before taking damage. Any reduction of damage by use of hay bales, potions, enchantments etc. will reduce the amount of experience gained. If a roll or graceful roll as been executed, you will gain 80XP per half heart of damage instead of 120XP. This calculation uses the damage that would have been taken if you had not rolled.

Feather falling will double the amount of XP you earn from falling, regardless of its enchantment level. Keep in mind that feather falling will also reduce the amount of base damage dealt when you fall.

Dodging an attack will give 120XP per half heart of damage dodged. So if you dodged an attack that would have dealt you 3 damage, it would give you 360XP.

Roll
Rolling is a passive skill which allows the player to reduce fall damage. Every level, the chance for a successful roll increases by 0.1%, with a maximum chance of 100% at level 1000. As rolling is a passive skill, it will be activated simply by taking fall damage. When activated, it can negate up to 7 damage points, or 3.5 hearts. Graceful Roll is an active skill; it is activated by sneaking (Shift key by default) while falling. It is only effective if the sneaking is started 20 blocks or fewer before impact. It can negate up to 14 damage points, or 7 hearts. As of version 2.1.0, Roll and Graceful Roll are considered the same skill, although both mechanics are still there.

Dodge
Dodging is a passive skill that halves combat damage taken; this includes Creeper explosions, Skeleton arrows, etc. Its max chance is 20%, at level 800; each level its chance increased by 0.025%.

Graceful Landing
Graceful Landing is a ability that allows you to negate most of fall damage when sneaking.

Extra

 * Video explanation - https://youtu.be/zn3O8ct9P6I
 * While damage taken from Ender Pearls is technically considered fall damage, no experience is granted for it. You can still do a roll/graceful landing to negate the damage though.
 * There is a five second cool-down period after teleporting where the user cannot gain any experience in Acrobatics.
 * https://www.youtube.com/watch?v=s_dXepIXSMI Click for Easy to use grinders]