Experience

Experience in Dota 2 is given by a unit on the enemy team that dies. Experience is used to level up, and it takes increasingly more experience to level up as a hero's level progresses.

A few important things about experience:


 * Experience is divided equally by all heroes in a 1300 range.
 * Experience from Hero kills has two parts, killing and assist. The killing experience will always give experience to the killer despite range (This is in addition to the divided experience inside the 1300 range).
 * Denied creeps grant reduced (- 50%) to all heroes within range.
 * Denied heroes grant no experience or gold to anyone.
 * Heroes take their share of experience even after level 25, even though they cannot use it.
 * Building kills grant experience.
 * Summoned units (units created by spells or items) give 50% experience.
 * You cannot get experience while dead (with the exception of when you have a Bloodstone, which grants you experience in a 1000 radius of where you died until your next respawn)

Leveling
A hero levels up by acquiring experience points from enemies (including Creeps, Towers, and summoned units) which die nearby. When a hero levels, its attributes get increased according to that hero's individual attribute bonuses, and it gains ability point. The ability point can be spent on any of the hero's spells which has not been maxed out, or to increase the hero's attributes by an additional 2 points each (Strength, Agility, and Intelligence). Ability points carry from level-to-level; if a hero levels up multiple times without spending ability points, they are retained for future use.

The amount of experience required to level up is generally equal to the upcoming hero level * 100. For example, to increase a hero's level from 1 to 2 (the first level "gained", as each hero starts the game at level 1) a hero requires 200 experience points, while leveling up from 24 to 25 requires 2500 experience points. In patch 6.75 this rule got an exception for reaching the levels 7 and 8, as they now require the same 600 experience as level 6. This oddity is ironed out by the unusual high 1200 xp required for level 9. The reason behind this is to help support-type heroes sustain their usefulness throughout the midgame by making their spells have a greater impact than otherwise. A similar change was made in patch 6.78 to level 11, allowing heroes to get their second level ultimate sooner. Simultaneously the experience for level 12 was increased to keep heroes at level 11 longer. There is only a small amount of experience needed for level 13 which returns the total experience to match the level * 100 formula.

Hero Killing
Like other units, when an enemy hero is killed, allied heroes within 1300 range receive an experience reward. However, the experience of killing has two parts: killing experience and assist experience. The former one is equally divided by allied heroes within 1300 range and the killer. The later one is only determined by appearance: even you're the killer, if you're not in 1300 range, you won't get this part. They also have different formulae: the killing experience is fixed while the assist one is related to the dynamic experience of both teams and killed hero.

Killing Experience
When an enemy hero dies, allied heroes within 1300 range and the killer (if not in the range) receive an experience reward. The experience calculated below is total, it needs to be equally divided. The formula is as follows: If 'x' is the level of the killed hero, the amount of experience gained is:
 * For levels 1-5: f(x) = f(x-1) + 20(x-1); f(1)=100
 * For levels 6 and further: f(x) = f(x-1) + 100; f(5) = 300

Or you can combine them into one formula: f(x) = (10x2 - 10x + 90) H(5.5 - x) + (100x - 200) H(x - 5.5)

Assists
When an enemy hero dies, allied heroes within 1300 range receive an experience reward. The formula is as follows:

XP Difference is defined as ( EnemyTeamXP - AlliedTeamXP ) / ( EnemyTeamXP + AlliedTeamXP ) and has a minimum of zero.

Denying
Denying occurs when a hero lands a killing blow on an allied unit. Heroes can only target allied creeps if they are under 50% health, and can only target allied heroes if they are afflicted with certain debuffs. Enemy heroes in 1300 range split half the usual experience bounty. Denying an allied unit prevents the opponents from earning gold.