Difficulty in Risk of Rain 2 can refer to two things: initial difficulty and scaling difficulty.
Initial difficulty in Risk of Rain 2 is selected along with the players' Survivors and loadouts before starting a run. The three initial difficulties are Drizzle, Rainstorm and Monsoon.
Drizzle is an easier initial difficulty designed for a more relaxing experience.
- Time affects scaling difficulty at 50% the normal pace.
- Players have a +70 bonus to armor.
- Players' health regeneration multiplier starts at
Rainstorm is the default initial difficulty of the game.
Monsoon is the hardest initial difficulty designed for players who seek a challenge.
- Time affects scaling difficulty at 150% of the normal pace.
- Players' health regeneration multiplier starts at
- The Deicide and The Calm challenges can only be obtained on this difficulty.
- The mastery challenges for Survivors' alternate skins can only be obtained on this difficulty.
Eclipse is an alternate gamemode that adds stacking challenge modifiers to successive runs to create difficulties "beyond" Monsoon. For more information, see the Eclipse page.
Scaling difficulty is a core mechanic of Risk of Rain 2. As a run progresses, the difficulty will steadily rise, making enemies both stronger and more numerous.
The steadily rising difficulty is represented in-game through a bar in the top right corner of the screen. This bar shows the selected initial difficulty, the current run timer and the current status of the scaling difficulty. As the bar progresses, it will pass through multiple named sub-difficulties in order:
- Very Hard
- I SEE YOU
- I'M COMING FOR YOU
The HAHAHAHA sub-difficulty has a maximum of level 99.
In addition to the increase over time, every time an environment is completed (aside the Bazaar Between Time and Void Fields), the difficulty will jump forward, which will cause a spike in difficulty, and the bar will also increase faster. This increase is exponential, which means that as more Loops are completed, the game becomes exponentially harder.
The game files mention a "Very Easy" difficulty, although it is never seen during normal gameplay.
Effects of difficulty
Each of these sub-difficulties contain two intermediate "notches". Every time a "notch" is reached, or the next sub-difficulty is reached, enemies will level up, which is indicated by a visual effect and a level-up sound similar to a player level-up, although with a lower pitch. Just like players, enemies gain 30% health and 20% damage (compared to their base values shown in the Logbook) per additional level.
In addition to enemy levels, the difficulty also affects the spawn rate of enemies. As the sub-difficulties progress, enemies will spawn faster and in greater numbers. After a while, stronger enemies will start to spawn outside of the Teleporter Event, including mini-bosses (such as Greater Wisps) and Teleporter Bosses (such as Stone Titans). Higher difficulty also increases the frequency of Elites, and even allows for elite mini-bosses and Teleporter Bosses.
The core mechanics of scaling difficulty do not change in multiplayer, but two numerical changes are applied:
- The initial difficulty is higher, although this is not reflected on the bar. This is why the spawn rate is higher and chests are more expensive. Enemies still start at level 1, however.
- Time has a greater effect on scaling difficulty (the bar advances faster). This is reflected on the bar, although the effect is subtle for a low player count.
Unlike the first game, playing multiplayer solo (starting a server but not waiting for other players) will not change the scaling compared to "true" singleplayer.
The Math of Scaling Difficulty
The effect of difficulty on the game is centralized in a global number called the difficulty coefficient (coeff for short). This coefficient is constantly re-evaluated and it is calculated as follows:
In these formulas, the variable
- playerCount is equal to the number of players in the game (including disconnected players).
- difficultyValue is equal to 1 for Drizzle, 2 for Rainstorm, and 3 for Monsoon.
- stagesCompleted is equal to the number of stages completed (including A Moment, Fractured and Gilded Coast, but NOT the Bazaar Between Time or Void Fields). This is the same number that shows up in the statistics screen at the end of the run.
- timeInMinutes is the amount of minutes since the run started, incremented every second.
Therefore, in non-modded lobbies, coeff will start at an initial value of 1 to 1.9 depending on the number of players. The bar will then progress linearly as time increases, increasing faster depending on the initial difficulty and/or the player count. Every time players enter a new environment, coeff increases by 15% of its current value, which causes the jump on the bar.
It is interesting to note that although sub-difficulties do not have any tangible effect on gameplay, they do signal an increase of coeff by 1 (actually 0.99 but by the time the difference becomes significant, the sub-difficulty is already in its final stage). For example, in singleplayer the Easy sub-difficulty represents a range for coeff from 1 to 2, while Medium is 2 to 3, etc.
Effect on enemy level
The enemy level is calculated using this formula:
No matter the number of players or difficulty, this means that enemies always start at level 1. As coeff, rises however, so too do enemy levels. The faster that coeff increases, the more the effect becomes pronounced - especially when Looping - as the exponential rise in coeff is translated to enemy levels and therefore stats.
Effect on money costs
Whenever an environment starts, the cost of an interactable is derived from the following formula:
The base cost is equal to what the interactable would cost in the first environment of a singleplayer run (for instance, the base value of a Small Chest is $25). Since coeff starts at a higher value in multiplayer, chests are also equally more expensive.
Effect on enemy rewards
Whenever a monster spawns, its reward is directly multiplied by coeff :
See Directors for more information on monster value and reward multiplier.
Effect on spawn rate
Spawns are managed by the Directors, which are advanced systems that are responsible for spawning a variety of enemies matching the difficulty.
Over time, a Director accumulates a number of "credits" that increase linearly with coeff. Regularly, the Director will pick a random enemy to spawn depending on the environment spawn lists and spend credits to spawn a group of up to four. Weaker enemies such as Lemurians have a low cost, while bosses like Magma Worms have the highest. Additionally, spawning Elite monsters is more costly: Blazing, Overloading, and Glacial Elites cost 6 times as much as a normal monster, and Malachite and Celestine Elites cost a whopping 36 times more.
While coeff is low, a Director will only spawn lone, weak enemies. As coeff rises, however, so does the Director's budget. This allows it to spawn larger groups of enemies, stronger enemies, more Elites, or more expensive enemies.
A Director will also avoid spawning an enemy group that is "too cheap" for its current credit (defined as the cost of a full pack of elites, so either 36 or 216 times the original enemy cost depending on the current stage). This is why as time goes on, weaker enemies are less and less common and even disappear completely after a while. In previous versions, this meant that for particularly deep runs, coeff became so large that even bosses became too cheap, which caused strange behavior such as Teleporter Bosses failing to spawn. Eventually, stages would be completely empty as coeff reached into the thousands and the Directors endlessly accumulated credits they refused to spend. Now, to ensure that the Directors always have something to populate the map with, they will check if the selected monster group is not the most expensive they could spawn before they deem them too cheap to use.