The answer up front: on death you lose everything you brought and everything you looted except what is inside the safe container - in both modes. Collected Active Matter also drops in the world where others can absorb it. Investigation and contract progress is kept. Isolated lowers variance (AI only); Open pays the locked objectives and better loot.

What You Lose vs Keep on Death

StatusItems
GoneWeapons, armor, ammo, meds, and loot in pockets and backpack - plus collected Active Matter, which drops as globules others can absorb
KeptEverything inside the safe container (teleported to Shelter). One oversized item can overflow the container volume. Investigation and contract progress
If you can get back upFirst revive costs Active Matter, later revives cost more. A placed respawn beacon brings you back on the map; enhanced beacons can return you in kit to fight for your bag
Container first: dog tags and the one item you cannot afford to lose go in first. You can turn off auto-evac of the safe container if teammates are about to revive you - if the whole squad dies, that loot is contestable.

Isolated vs Open: The Decision That Actually Matters

IsolatedOpen
Other playersNone - AI operatives and monsters onlyYes - queue Any / Solo only / Squad only
Death penaltySame gear + AM lossSame
Loot / tokensWeaker loot, fewer tokensBetter loot, player kits, higher-paying dailies
ObjectivesBaseline - many investigations workExpert / High-Value / Qualified Field Work often Open-only (padlocked in Isolated)
MapsMost maps - some Unstable / Gigastructure content is Open-onlyFull contested set
AccessUnlimited - the old pass / 24h limit info is outdatedUnlimited
The real Isolated tax: Expert milestones disabled means missing roughly 1.5k tokens a day per map if you skip Open entirely.
Choose Isolated
Learning, testing, careful runs
Learning a map, testing a kit you cannot replace, finishing investigations without extract campers, or one careful run.
Choose Open
Objectives and loot
Expert / High-Value objectives, better crates, player loot, Unstable Zone maps. Solo players: queue Solo only, autofill off. Open + Solo is not Isolated - other solos still appear.

1Before You Ready Up

2In-Raid Death Management

Isolated learning kit: cheap shotgun or SMG, 4 mags plus ~120 spare, bleed stops, one beacon, container on. Isolated AI still dumps 40-60 kills on a long run - ammo panic is the usual Isolated wipe.

Common Mistakes to Avoid