Grismar's EVE Wiki : TrueSecurity

True Security

EVE uses a numerical scale from 0.0 to 1.0 to indicate relative security for solar systems. The relative security status of a solar system dertermines CONCORD response to acts of agression and provides a framework for the RulesOfEngagement. While the game client only displays a rounded one-decimal number, the game actually operates with a more finely grained system of security rating values, termed 'true security'. This article explains 'true security' and its implications.

You may also want to read the article on SecurityStatus, detailing other aspects of player and system security.

A system's true security value is a fixed number with 15 decimals, ranging from -1 to +1. You can look up a system's true security rating value at http://eve.grismar.net/ssec.

The displayed solar system security rating, ranging from 0.0 to 1.0, is simply the rounded true security value. True system security values < 0 are always rounded to 0.0.

Rounding has significant consequences for the RulesOfEngagement, which are biased towards greater security:

• If a true system security value > 0 is rounded up, the RulesOfEngagement for the system with the higher value apply. E.g., if you attack another player in a system with a displayed system security value of 0.5 that is actually rounded from a true system security value of ≥ 0.45, CONCORD will respond.
• However, if a true system security value > 0 is rounded down, the RulesOfEngagement for the system with the higher/actual value apply. E.g., if you attack another player in a system with a displayed system security value of 0.0 that is actually rounded from a true system security value of > 0 and < 0.05, you will lose corporation standing with Concord, i.e. lose SecurityStatus.

The following 14 systems that have a displayed system security value of 0.0 have a true security > 0 and < 0.05. That means that you will still lose personal SecurityStatus in these '0.0' systems:

Anath, Balas, Egbinger, Espigoure, Feshur, Hophib, Karan, Naga, Pemsah, Sakht, Skarkon, Vestouve, Yekh and Yiratal.

Rounding of true system security values also affects access to solar systems as detailed in StatusAndTravel. Again the rules are biased towards greater security.

• System access restrictions are based on displayed solar system security status values. If a true system security value > 0 is rounded up, access restrictions for a system with the higher value apply. E.g., a player with a personal SecurityStatus of -2.5 should be able to enter systems rated < 0.9 but cannot enter a system with a true system security value of ≥ 0.85 because that value is rounded to 0.9.

Keep in mind that solar system access is also based on the actual value of a character's personal SecurityStatus rather than a rounded value. A character's personal Status is displayed as a truncated number in the character sheet but gets displayed as a rounded number in the character information window when viewed by other players. Consequently, if you see someone with a personal SecurityStatus of -2.5 in a system rated 0.9, their actual personal SecurityStatus would in fact be < -2.5 and ≥ -2.45 and they are free to travel to 0.9 space without CONCORD interference.