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.

A server not having reached a specific Tier does not mean it is impossible to get gear from said Tier - it just makes it way tougher and rarer. Everyone is able to craft gear from the current and previous Tier the server currently resides in. While higher Tier items are still able to be crafted with the help of found blueprints, as well as advanced workbenches found in the Core

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"), introduces 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, or differently phrased, Tiers are subcategories of an Era.

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

Apart from visually representing the different Tiers, each Era effectively serves as an unlockpoint for new armor and new consumables and utility items. Unlike weapons and ammo, with new ones introduced every tier, new armors and consumables are unlocked only every 3 tiers. This makes breakpoints especially strong for Armor upgrades. As someone shooting a Tier 3 gun at someone already wearing 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.