Technology

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This article is for the PC version of Stellaris only.

Technology

**Technology**

 Engineering research

 Physics research

 Society research

*Technology* in Stellaris is divided into 3 research areas with each area corresponding with one of the research resources:  Engineering,  Physics and  Society. Additionally, each of the ~400 techs belongs to one of 12 subcategories divided between the areas (most appearing pre-dominantly in one area though not exclusively).

The user interaction aspect utilizes a *card shuffle* approach rather than a traditional *tech tree* presentation, thereby introducing an element of semi-randomness into the system.

Each technology has a *base cost* which is modified by  empire size. The research cost is increased by **0.1%** for each point of empire size above 100.

## Research areas & fields

There are three different main *research areas* in-game, with each area corresponding with one of the research resources. Additionally, each research area has multiple subcategories, for a total of 13 such subcategories, and every tech belongs to one of these subcategories.

The areas and their subcategories are as follows:

 **Physics research**

* Computing: Science Labs, research, science ships, ship computers, point-defense, sensors.
* Field Manipulation: Power Plants, shields, some strategic resources.
* Particles: Ship reactors, energy weapons, FTL, some strategic resources.

 **Society research**

* Biology: Food production, leader lifespan and policies, species modification, army types, some strategic resources.
* Military Theory: Fleet command limit, naval capacity, army buildings and statistics, claim cost.
* New Worlds: Habitability, tile blocker clearance, terraforming, starbase capacity.
* Statecraft: Unity, edicts, leader pool and recruitment, planetary and empire capitals.
* Archaeostudies: Minor artifacts, archaeotechs.
* Psionics: Exotic mid- to late- game technologies. Unlocked through the  **Psionic Theory** technology.

 **Engineering research**

* Industry: Mineral production and storage, robots, building construction.
* Materials: Armor, strategic resources.
* Propulsion: Kinetic and explosive weapons, thrusters.
* Voidcraft: Ship types and hulls, starbases, strike craft.

## The card system

Although the underlying technology system is based on the familiar *tech tree* structure, it does away with its standard interaction/presentation in favor of the *card shuffle* approach. This injects a semi-random element into research, making it somewhat less predictable as well as less linear.

Whenever the player is prompted to initiate a research project, the game gives them a "hand of cards" consisting of a semi-random selection of technologies available for research, which are picked randomly from a hidden "deck of cards" consisting of all valid research options that can appear.

Technologies are divided into 6 levels (T0 to T5) of advancement. Higher tier technologies require obtaining a certain number of technologies from the preceding tier in the same area of research (set at 6 for all tiers) before they become available as research alternatives.

Every time the player meets the requirements for a given technology to become obtainable, the technology in question is added into the main "card deck" and will then have a chance of appearing in the "card hand" whenever the game draws a new hand for the player to pick from. There is one basic parameter affecting a tech's chances of appearing in a given card hand:

* *Weight* – A base value denoting the *relative* chance (out of all the valid options) of a particular technology to be drawn as an alternative. This may be further modified by an empire's composition (ethics, civics, etc.) and its current state (scientist's traits, past tech, etc.).

To further increase variation, a tech which appeared as an alternative in the previous card hand will have its weight multiplied by 0.5 in the next draw.

As a rule of thumb, the more advanced a technology is, the lower its weight (and the higher its cost). Systematically important techs (e.g. terraforming) have a higher weight (typically between 150% and double normal) to help ensure empires get a chance to research them, whereas **rare technologies** have significantly lower weight (typically one-eighth normal without the matching expertise). Some factors increase the weight of rare techs:

* Being in a level 3 or higher  Research Cooperative federation with another member who knows the tech doubles the weight.
* The  Technological Ascendancy ascension perk increases the weight of **rare technologies** by 50%.

Research can be automated, in which case the game will pick the cheapest technology to research unless a rare technology is available for research.

### Example

Let's assume the game draws a card hand of 3 techs:  Armored Torpedoes,  Autocannons, and  Exotic Gas Refining. Additionally, the lead engineering scientist has a  Propulsion field expertise (matching Armored Torpedoes), and the previous card hand had  Autocannons as an available option.

# Total weight
Armored Torpedoes weight

⋅

expertise bonus

Autocannons weight

Exotic Gas Refining weight

{\displaystyle \text{Total weight} = \text{Armored Torpedoes weight}\, \cdot\, \text{expertise bonus} +\, \text{Autocannons weight}\, +\, \text{Exotic Gas Refining weight}}

# Total weight
60
⋅
1.25

75
2

# 170
75

37.5

# 170
282.5

{\displaystyle \text{Total weight} = 60 \cdot 1.25\, +\, \frac{75}{2}\, +\, 170 = 75 +\, 37.5 +\, 170 = 282.5}

If these were the only three valid techs and only one tech were to be drawn, then each tech's chances of being drawn would be **26.5%**, **13.3%**, and **60.2%** respectively (rounded to 1 decimal place). Realistically there are usually many more valid picks and so the probability of picking any given tech is significantly lower than the figures given here.

### Research alternatives

Each card hand drawn will contain 3 research alternatives, which may be further increased by a variety of factors. Additionally, some research cards may be gained as *permanent alternatives*. They appear below the regular alternatives and are distinguished from them by a **golden** border surrounding the tech card's bezel. These alternatives are usually acquired (along with some partial progress) through post-battle debris analysis, from special projects, or from event chains. These options will always appear as available options when drawing a new card hand and will remain as such until completed.

If need be, it is possible to change an on-going research project at any point – without losing research progress – and continue researching it at a later time. It is important to note, however, that the saved progress does *not* scale with changes to technology costs (for better or for worse). This tends to lead to the tech's completion percentage getting lower as the empire increases its  empire size.

Unlike a permanent alternative, there is no guarantee that the technology in question will appear in the next card hand drawn.

The number of research alternatives can be increased by the following:

## Research progress

In general, *research time* can be summarized as the following formula:

# Research time
∑

Research cost
−

Partial research done

Monthly research progress

{\displaystyle \text{Research time} = \sum\frac{\text{Research cost} -\, \text{Partial research done} }{ \text{Monthly research progress} }}

Research progress is one of the key elements affecting the time it takes to discover new technologies. It is formulated as follows:

# Monthly research progress
Research resource produced

⋅

∑
Research speed modifiers

min
[
Research resource stored
,
Research resource produced
]

{\displaystyle \text{Monthly research progress} = \text{Research resource produced}\, \cdot\, \sum\text{Research speed modifiers}\, +\, \text{min}[\text{Research resource stored},\text{Research resource produced}]}

While it is possible for the *monthly research progress* to remain constant during the course of researching a certain technology, it is more than likely to fluctuate – for better or for worse – due to consequences of various actions (such as exploration, empire development, expansion, etc.). This, in turn, may increase or decrease the total research time of a given tech.

### Example

The empire from the previous examples (same setup) has just finished debris analysis granting it **+10%** research progress in  Armored Torpedoes along with  **+1000** engineering research (stored research).

This setup generates the following monthly research progress:

# Monthly research progress
24

⋅

(
1

0.05

0.15
)

min
[
1000
,
24
# ]
52.8

{\displaystyle \text{Monthly research progress} = 24\, \cdot\, (1\, +\, 0.05\, +\, 0.15)\, +\, \text{min}[1000, 24] = 52.8 }

Assuming no further changes impact the above setup, the total research time of the tech would be:

# Research time

1862

−

1862
⋅

0.1

52.8

=
31.74 months

{\displaystyle \text{Research time} = \frac{1862\, -\, 1862 \cdot\, 0.1 }{ 52.8 } = \text{31.74 months}}

**Note:** *Partial research* can refer to debris analysis, previous research, event rewards, etc.

## Debris

Debris has a chance of spawning when at least a ship from enemy fleet is destroyed. They are capable of providing progress on most of the components, weapons and defences, but not ship upgrades. The following are examples of technologies that cannot be obtained from debris:

* Standardised Corvette Patterns
* Improved Corvette Hulls
* Destroyers
* Synapse Interceptors
* Psionics Shield

Each component can only spawn if the components are above the technology level of the attacker. Each component will provide 10% progress on the technology, or 10% progress on the pre-requisites technology if the pre-requisites technology is unresearched.

###  Salvager trait and  Scavengers civic

The  Scavengers civic  Enables the *Research & Salvage Debris* debris policy.

Both  Salvager trait and  Scavengers civic increase the chance for a salvage to yeld a ship:

# Chance salvage ships from debris
(
Salvage-chance-add
⋅
100
Base Chance
Salvager bonus
Scavengers Bonus
)
⋅
Salvager Trait Level

{\displaystyle \text{Chance salvage ships from debris} = ( \text{Salvage-chance-add} \cdot 100 + \text{Base Chance} + \text{Salvager bonus} + \text{Scavengers Bonus}) \cdot \text{Salvager Trait Level}}

Salvage-chance-add is the sum of is additional external bonuses. Base Chance = 10; Salvager bonus = 5; Scavengers Bonus = 5; Salvager Trait Level = 1; 2; 3.

With Salvage-chance-add = 0:

 **Scavengers Bonus** | 15
 **Scavengers Bonus** | 20

## Research output

Each *research area* employs the use of a different research resource.

Each of these individual resources has a base production of **10** research points a month. Most research output comes from pops working the appropriate Jobs or research stations on space deposits.

Research production can be modified for total empire production, job output, research stations (and starbase buildings), or for  Researcher category jobs. The following modifiers apply to all three areas of research:

Each research area has specific modifiers as well, with a few modifiers applying to two areas.

### Stored research

Whenever research output is not actively used, it accumulates as *stored research*. Stored research also includes research resources gained from other avenues, such as debris analysis, anomalies, events, etc.

This allows for a more "relaxed" approach research by eliminating the possible loss of research points due to forgetting to pick a research project while, at the same time, also simulating accelerated periods of research (as opposed to sudden "jumps") caused by newfound knowledge sources. The current storage levels can be seen by hovering over the appropriate resources.

Stored research effectively doubles research speed, as it is spent at a rate matching current output, as long as there is enough stored research.

Example
An empire produces  **+24** engineering research each month and has just finished a debris analysis granting it  **+1000** engineering research (stored research).

# Stored research expenditure length

1000
24

=

41.67 months

{\displaystyle \text{Stored research expenditure length} = \frac{\text{1000}}{ \text{24}} =\, \text{41.67 months}}

The empire will supplement its  engineering research by an additional **+24** research points for the first 41 months and by another **+16** research points in the following month, after which the stored  engineering research will be completely depleted.

## Research speed

*Research speed* represents a given expertise in a particular research area or field leading to shortened research time of related technologies.

Research speed boosts the effective research production in the following manner:

# Effective research production
Research resource produced

⋅

∑
Research speed modifiers

{\displaystyle \text{Effective research production} = \text{Research resource produced}\, \cdot\, \sum\text{Research speed modifiers}}

The most immediate sources of research speed modifiers are the scientists in your council. As the applied bonus depends on a scientist's skill level and overall traits, it is recommended to assign newly recruited scientists to command a science ship. Scientists on exploration duty tend to gain experience faster and, if one is in luck, they may also gain a new trait beneficial to research while leveling up.

Example
An empire is a  Materialist and produces  **+24** engineering research a month. It has a lead engineering scientist with a  Propulsion field expertise while researching  Armored Torpedoes.

# Effective research production
24

⋅

(
1

0.05

0.15
)

=
28.8

{\displaystyle \text{Effective research production} = 24\, \cdot\, (1\, +\, 0.05\, +\, 0.15)\, = 28.8 }

**Note:** A research area without a leading scientist receives a **−25%** penalty to research speed.

Research Speed is affected by the following permanent or renewable modifiers. Other temporary modifiers to research speed may be gained from events or anomalies.

## References

1. ↑ See Stellaris/common/technology/tier/00\_tier.txt for details.

**Game concepts**