Server Progression

During the lifetime of a Season, more advanced gear is unlocked and used. When a new season starts, the Server initially starts at Tier 2. Tier 2 currently includes very crude 19th century weapons. The tech-tree goes from Tier 1, all the way up to Tier 10, Tier 1 being the very first mainstream projectile weapons humanity created with Tier 10 being mostly futuristic weapons.

Tier

Each tier introduces more recent gear to the table. Usually in form of weapons and ammo, while every third tier (also called every "Era"), introducing new armors, drugs and other consumeables or utility items.

Era

Era's are directly dependent from Tiers. An Era is basically a collection of Tiers.

Era 1 is Tier 1 - 3
Era 2 is Tier 4 - 6
Era 3 is Tier 7 - 10

Apart from visually representing the different Tiers, each Era effectively serves as an unlockpoint for new armor and new consumeables and utility items. Unlike weapons and ammo, with new ones introduced every tier, new armors and consumeables are unlocked only every 3 tiers. This makes breakpoints especially strong for Armor upgrades. As someone shooting a Tier 3 gun at someone already Era 2 armor (An armor designed for the whole row of Tier 4 to Tier 6), will do considerably less damage then onto someone with Era 1 armor.