Diminishing returns (DR) refers to the mechanics used to prevent disruption to the economy, from bots or exploits, which would otherwise disadvantage legitimate players. There are several types of DR in the game, each of which is character-based with the exception of dungeon DR, which applies to the entire account. Although DR could affect most activities that have potential for abuse, very few players will experience it during normal play.
DR was applied to dungeons due to their ability to be repeated quickly. Similarly, it is applied to Dynamic Events to limit players from exhaustively farming one area, reduce congestion in one particular map, and to discourage forbidden activities such as botting.
To reduce the impact of DR on a player's account, change maps and participate in different events. Swapping to a different character allows the player to get maximum rewards, although the original character will retain its DR until cleared.
- Dungeons, in which the completion rewards for an account are cut severely after the first run for each path, as well as the end rewards being reduced if you complete too many too quickly.
- Open world:
ArenaNet has never shared the precise details of how diminishing returns is implemented in Guild Wars 2, with the exception of dungeon reward DR. From various posts by the company's staff, players have pieced together the general concepts:
- The more often a character loots from similar foes within an area, the more quickly DR triggers.
- Once triggered, the impact of DR will increase until you won't get any loot at all anymore.
- The only way to "remove" DR is to go somewhere else for a length of time that is partly random and partly dependent on how much DR that character has. Usually, it lasts no more than 15-20 minutes if the character actively participates in other content. AFK'ing on any map for about 30 minutes will reset it as well.
- Except for dungeons, DR is character based, which means:
- Swapping characters results in a fresh start, with no DR.
- Each individual character must leave the affected area for a time in order to reset the DR, i.e. swapping to a second character does not help reset DR on the first.
- First tests lead to the conclusion DR for loot through mob killing is triggered when killing more than 5 mobs per minute on average.
Dungeon DR reduces the completion rewards for completing the same path more than once. It affects the direct rewards for completing each path and applies to experience, karma, and Empyreal Fragments. Unlike other forms of DR, dungeon DR is account-based, meaning it cannot be avoided by running the same path on multiple characters. It works in two ways:
- The bonus reward of 80 tokens is only awarded once per path per day, resetting at the same time as the dailies. For example, one can finish a path five minutes before reset and the same path again 35 minutes after reset, and receive 160 tokens, the full reward from both completions.
- Completing the path consecutively triggers the dungeon DR, which reduces the base reward for that path by half until reaching a minimum value. Each stack of DR takes an hour to clear and is not removed by daily reset.
- The end rewards are reduced as well if you complete too many paths too quickly.
Event & Map DR
Another type of Diminishing Returns applies to events in the open world. It affects the amount of coin, experience, karma, and Map Bonus Rewards. Again, ArenaNet will not offer the details of how it works and some of the mechanics changed with the release of Heart of Thorns. Presently, there is no consensus on the specifics, so the following illustrates the community's best understanding:
- Event DR applies when a character repeats the same event multiple times without a break. There is little data to show how quickly it triggers.
- It also applies to completing multiple events within a single map in core Tyria. Again, there is little data to indicate whether it differs by event, the amount of time spent on the map, or the value of Map Bonus Rewards. There are reports that it triggers with as few as 10 events or 30-45 minutes of time spent doing events.
- Event DR is soulbound, so each character starts fresh for each event or each map.
- As with loot DR, clearing it requires leaving the relevant map or doing other events.
- Event DR can be cleared after completing any other event,
- There is little data that confirms how to clear Map DR. Based on anecdotal reports, it might take one or more of the following: spending an equivalent amount of time spent in another map, doing a set number of events on another map or another part of the same map, or after server reset.
- Both event and map DR set in quickly once triggered. It is easy to see its effects by comparing the amount of karma or XP, as well as the absence any boss chests or a decrease of other rewards.
- There is no DR associated with salvaging.
- There is strong evidence that DR does not apply to using of the Mystic Forge or opening containers.
- There is no evidence that DR applies to any other sources of loot, including PvP rewards.
- Originally, DR was character-based in dungeons. 
- ^ https://forum-en.gw2archive.eu/forum/game/gw2/Let-s-Start-the-Karma-DR-Dialogue/page/5#post338355 Jon Peters, GW2 Forums
- ^ John Smith posted that, "There’s virtually no DR active on any given day."
- ^ a b Dungeons still have diminishing returns, reddit.com
- ^ https://forum-en.gw2archive.eu/forum/archive/bltc/Stealth-nerf-on-ecto-drops/first#post693957 John Smith, GW2 Forums
- ^ https://forum-en.gw2archive.eu/forum/game/dungeons/Dungeon-DR-is-now-account-bound-never-got-it-before-today/first#post319465 Jon Peters, GW2 Forums