Achievements (previously known as Tasks and Achievement Diaries) are challenges that players may complete in order to earn rewards. The Achievements system consists of Achievements grouped under skills, areas, PvM, and completionist categories. As of 16 March 2018, there are 1,823 achievements of which 1,794 are visible and the 29 Feats achievements are hidden until achieved.
To access the Achievements system, players should click on the Hero icon in their interface. In Legacy-mode players need to click the Settings-icon to access this. Doing so will bring up the Hero interface. By opening the Achievements tab, a player can view an overview of the Achievements (including the Path System), list of all Achievements and a tracker for Achievements.
The skills Achievements list milestones in each of the skills. The last Achievement in all skills is reaching level 99, except for Dungeoneering, Slayer, and Invention that continue until level 120. The Skilling Pets achievements list achievements for obtaining each of the skilling pets and the titles for obtaining those. The Divination achievements list achievements Divination tutorial achievements. The Fishing achievements list achievements regarding Deep Sea Fishing.
The Exploration Achievements are based around various areas of the game, asking players to complete a variety of tasks around these zones. Almost all of the sub-categories in this category offer special rewards for completing a meta-achievement: a special wearable item, experience lamps, and various bonuses in the specific area. Additionally, most Achievements in this category are split into one of five difficulty types: Beginner, Easy, Medium, Hard, or Elite.
Only Lumbridge has a beginner level and no elite level, since it was the original starting area. These are the latest iteration of the original "Achievement Diaries".
The Combat achievements are based around various kinds of combat, varying from fighting bosses solo, in groups, killing them often, collecting the boss pets, or general achievements related to combat.
The Minigames achievements are based around the various minigames and activities in RuneScape.
The first achievement set (Karamja) was released on 8 May 2007. It was originally named an Achievement Diary and had three difficulty levels: Easy, Medium, and Hard. The interface resembled that of the quest list and was actually a sub-menu of the Quest Tab. As with quests, each diary turned green once completed. Achievement diaries were later split into a separate interface tab, merged into the Noticeboard tab, and eventually put in the Hero interface in the New Interface System.
A total of six more Achievement Diaries were later released. The Ardougne Tasks, released on 20 October 2009, was the first set to have a fourth difficulty level, Elite. Elite Tasks were added to most other areas on 7 September 2010.
On 24 November 2010, the system of Achievement Diaries was changed into the Task system. The interface was redesigned, extra rewards were added, and more tasks (not considered to be part of the Lumbridge and Draynor Tasks set) were released for the Lumbridge area, meant as an introduction to the Tasks system for new players. Since then, more tasks have been periodically added to this generic set. Many of these "Miscellaneous" tasks are very simple to complete (e.g. Use the "Run" feature) and as such have a Beginner difficulty level.
On 29 August 2017 the interface was further reworked, adding a new system called RuneScore to track the player's achievement progress, adding new categories and achievements, and fixing numerous complaints with the previous overhaul.
- Seven areas that do not have a current task list are still displayed as locations in the tasks tab when visiting the areas. These areas are the Gnome Lands, Feldip Hills, Keldagrim, Dorgesh-Kaan, Piscatoris, Islands (Entrana, Ape Atoll, Crash Island, Void Knights' Outpost, Braindeath Island, Mos Le'Harmless, Harmony Island, Rock Island Prison and Iceberg), and the Outer Planes (Zanaris).
- If all the tasks for a higher group (Hard tasks, for example) are completed without completing the ones that precede it, then the rewards for those higher tasks are not rewarded until the lower tasks are completed as well.
- As of 4 December 2017, there are 1,779 achievements. In September 2017 there were 1,654 achievements, May 2017 - 1,203, January 2016 - 657, September 2014 - 603, May 2012 - 533, February 2012 - 426, and November 2010 - 417.