Discipline

Discipline was an Armor stat that governed how quickly your Grenade ability recharged. It also boosted the grenade energy you gained from external sources. Under the older system each stat gave benefits at 10-point tiers, and the grenade cooldown fell from 1:43 at tier 0 to 0:32 at tier 10 for standard grenades, with Stasis grenades following a longer curve.

Armor 3.0

With Armor 3.0 in The Edge of Fate the stat was renamed Grenade and kept its core function. It still shortens the grenade cooldown and increases grenade energy regeneration from all sources. Once a stat passes 100 points, all further points add a secondary effect, which for Grenade is extra grenade damage. Stats cap at 200 points. Existing gear carried over at a 1:1 ratio, so 15 Discipline became 15 Grenade.

Where it came from

Discipline came from armor pieces and from armor mods such as the Discipline Mod (+10), the Minor Discipline Mod (+5) and Discipline-Forged (+3). Discipline-Forged can only be socketed once the Artifice Armor perk has dropped. Fragments also adjusted the stat, including Echo of Domineering and Ember of Char (+10 each), Echo of Undermining (-20), and several others at -10 each.