|This article relates to content added by Royalty (DLC). Please note that it will not be present without the DLC enabled.|
An ultratech machine that generates a sheet of exotic fields at high altitude, turning the sky opaque and blocking the sun.
Sun blockers block all light from the sun in a 10 world-tile radius of the map it spawns on, whether it be the player's colony or on an event map. Any maps in the area will be as dark as night all day, solar generators will not function, plants will not grow without another source of light, and effects that depend on the presence of sunlight such as UV Sensitivity genes will not trigger.
Even though most plants will die without sunlight, foraging for food during a caravan will still function as normal and plant will still spawn when settling or entering these maps for the first time. The normal day cycle also still occurs - plants will still go through their rest state at the usual times, sun lamps will turn on and off, and night owls will prefer their specific schedules. Lights from auroras still appear as normal and will provide light and positive mood, and eclipses still occur and will grant ideoligions with the Eclipse: Beautiful precept its usual moodlet.
Sun blockers will not spawn in mech clusters or as quest threats if a colonist or prisoner has an ideoligion with the Darkness or Tunneler memes. Note that this does not check for the presence of the Combat in Darkness or Lighting precepts, nor does it count the ideologion of slaves.
Multiple sun blockers affecting a given tile has no additional effect.
Sun blockers can be anything from a significant threat to a significant boon depending on the colony. If a colony relies extensively on power from solar generator or grazing animals for food, then destroying a sun blocker will be a priority. Usually, however, significant issues like crop losses leading to famine, take a while to accrue. This makes a sun blocker one of the less urgent condition causers, and one that can be adapted to long term even without DLC content - sun lamps, torches and lamps.
Sun blockers can be very powerful when combined with the Combat in Darkness: Preferred precept , providing a massive accuracy boost when outside. However, sun blockers still come with the work and move speed penalties in darkness and prevent regular crop growth. Work and move penalties can be completely mitigated by using Lighting: Darklight Preferred precept. Sun lamps can be used to grow crops, or you can grow nutrifungus, which does not need light (though still needs a roof over it). Both precepts have penalties while the sun still shines, and nutrifungus is disliked by most ideologies. However, fluid ideoligions can add memes / precepts after a sunblocker lands.
The Dark vision gene also negates the work and speed penalties of darkness. This comes with no downsides in the sun, other than the −1 metabolic complexity. Just the gene alone means you'll almost always have a speed advantage over human raiders, useful for kiting especially. However, the power and crop losses are usually not worth it unless you are already independent from sunlight. This gene is also redundant with the Lighting: Darklight Preferred precept.
When generated as part of a quest site, the site will not contain any electrical equipment, as these are usually powered by solar panels.