Experience



Experience, commonly abbreviated as Exp or XP, is a measure of progress in a certain skill. It is usually obtained by performing tasks related to that skill. After gaining a certain amount of experience, players will advance to the next level in that skill, which can result in new abilities, among other things.

Gaining Experience






Experience in a skill is obtained by performing a task related to that skill. Experience can also be gained by performing a task unrelated to the skill, such as completing a quest, participating in a random event, or playing a minigame or miniquest.


 * When a player rubs a lamp from a random event gift, the player gains experience equal to the level of the skill they select times 10. (E.g. a player's Woodcutting level is 50; they rub the lamp, choose Woodcutting, and receive 500 Woodcutting experience.)
 * When a player reads the Book of knowledge from the Surprise Exam random event, they receive to their chosen skill their current level times 15. (E.g. if a player's Attack level is 50, they would receive 750 experience from reading the book if they chose Attack.)

Players who help others using the Assist System can earn a maximum of 30,000 total experience every 24 hours, although the experience may be shared among many skills. Some skills cannot be shared through the Assist System (namely gathering and combat skills - Attack and Mining).

Players can continue receiving experience after level 99 in a skill: up to a maximum of 200 million experience. Once a player reaches this limit, they can continue using the skill but receive no additional experience. The maximum total experience is 4.8 billion (4,800,000,000) when a player has 200 million experience in all 24 skills. Currently, no player has reached this.

Until the Skills Interface update (on 12 November 2007), players with a level 99 skill could view the experience it would take them to earn level 100. However, even when "level 100" was "reached", the actual level remained at 99.

The experience gain rates one may obtain varies very much between skills. For example, with 99 agility it is difficult to get much over 70k agility xp per hour without brawling gloves, while making summoning pouches can give over 800k summoning xp per hour.

Exponential Growth
The amount of experience needed for the next level increases by approximately 10% each level. For example, 83 experience is required for advancement to level 2, while 91 experience is then required for advancement to level 3. The difference between 83 and 91 is 8. 10% of 83 is 8.3, which is approximately 8.

Note that a 10% growth factor may seem slow, but, as with all exponential growth, it expands rapidly to a massive 13,034,431 experience needed for level 99. Level 85 requires one quarter of the experience needed for Level 99 and Level 92 is the halfway mark, requiring 6,517,253 experience. This clearly demonstrates the experience gap that grows rapidly at higher levels. To gain 7 levels, one must gain all of the experience they gained to get to their starting level; thus, 92-99 is the same as 1-92.

The varying amount of experience needed to get from one level to another can cause some surprising experience rates to get from one level to another. For example, getting from level 98 to 99 is equal to getting from level 1 to level 75. However, it is worth noting that higher level activities in many cases award more experience than lower level ones, thus smoothening out the actual amount of time spent leveling at high contra at low levels a little.

Starting from level 28, the experience of getting to next level is approximately equal to 10% of experience of current level. It is still decreasing though, but much slower than the rate before level 28.

Combat skills
To calculate the experience gain for combat skills, a simple equation can be used:
 * Experience earned $$ = 4 \times d $$
 * where d = damage dealt to an opponent

This equation does not work for some opponents such as random events which give significantly less experience.

Hitpoints
To calculate the experience gain for Hitpoints, another simple equation can be used:
 * Experience earned $$ = 1.33 \times d $$
 * where d = damage dealt to an opponent

Monster Experience
An upper bound to the number of monsters required to level up a combat skill can be calculated as follows:
 * Number of monsters $$ = \frac {E} {4 \times H} $$
 * where E = experience required to level up
 * and H = monster's number of hitpoints

Note that this only gives an upper bound because monsters may recover some hitpoints during the battle, in which case more than H hitpoints are dealt.

Equations
The equation below calculates exactly the minimum experience needed for a given level:


 * Experience Required $$ = \left \lfloor \frac{1}{4}\displaystyle\sum_{n = 1}^{L-1} \left\lfloor n + 300 \times 2^{n/7} \right\rfloor \right\rfloor $$, where L = current skill level
 * Note that $$\lfloor x\rfloor$$ means the greatest integer less than or equal to x''.

In computer code this could be written as (an example is given using the PHP language):

function getXP($lvl) {   $total = 0; for ($i = 1; $i < $lvl; $i++) {       $total += floor($i + 300 * pow(2, $i / 7)); }

return floor($total / 4); }

The above equation can be approximated with minimal rounding error as:


 * Approximate Experience Required $$ = \sum_{n = 1} ^ {L - 1} \left( \frac {n} {4} + 75 \times 2 ^ {n/7} \right) $$, where L = skill level

This approximation can then be used to find the maximum additional experience required to level up:


 * Additional Experience Required to Level Up $$ = \frac {L} {4} + 75 \times 2 ^ {L/7} $$, where L = current level

Example
You want to find the experience that it would take to level up from 28 Strength to 29 Strength:


 * Additional Experience Required to Level Up $$ = \frac { \left( 28 \right) } {4} + 75 \times 2 ^ { \left( 28 \right) /7} = 7 + 75 \times 2 ^ {4} = 7 + 75 \times 16 = 1207 $$

So it would take at most 1207 experience points to get from level 28 to level 29.

Table
The following table shows the relationship between level, the experience required for that level, and the experience difference from the previous level: