This article is about planet difficulty. For character difficulty modes, see Difficulty mode.
See Tier for additional information about planet difficulty.
Difficulty (or threat level) is a characteristic possessed by planets.
Difficulty affects the types of monsters that appear on the planet - for instance, Inconceivable planets usually have fire-related monsters - and the amount of hitpoints and damage they have (see NPC and Monster for the exact effects of threat level on health and damage).
Difficulty also affects the types of blocks, biomes and dungeons that appear on it: the higher the difficulty, the harder blocks become to harvest at surface level and/or deeper underground and the tougher the guards that spawn in dungeons become; as well as the type of loot that comes from chests.
Certain ores and biomes can only appear at specific planet difficulties. Coal, Copper Ore, Silver Ore, Gold Ore, and Diamond deposits appear on almost all planet types, but other ores only appear at one or two different threat levels.
Villages can appear on all planets that are at least Moderate threat level, but the contents of villages varies in part with planet difficulty because Treasure generation often depends in part on planetary threat level.
A planet's difficulty is generally determined by its star (for more information, see Stars). Here is a list of difficulties from least to greatest:
Planet Threat Levels
|Threat Level||EPP needed||Planet Biome|
|Unknown (Tier 0*)||Breathing EPP||Moon|
|Low (Tier 1)||None||Garden, Barren, Asteroid Field|
|Moderate (Tier 2)||None||Desert, Forest|
|Risky (Tier 3)||None||Ocean, Savannah, Snow|
|Dangerous (Tier 4)||Radiation EPP Upgrade||Jungle, Toxic, Mutated|
|Extreme (Tier 5)||Heating EPP Upgrade||Arctic, Tundra, Midnight|
|Inconceivable (Tier 6)||Cooling EPP Upgrade||Volcanic, Magma, Decayed|
- The Unknown threat level is meant to be ambiguous, in that no threat exists whatsoever until you acquire Erchius Fuel or bring some with you. It is actually registered in the game files as Tier 1, the lowest tier.