Caliber
Operators
Caliber is a squad shooter with specialist jobs. If four people lock assault, you will miss smokes, heals, and a breach. Pick a role.
PvE wants utility
Missions punish missing a medic or a demo. Bring the gadget the room needs, not the operator with the coolest trailer.
Ammo crates and mark-up tools save wipes more than a slightly faster TTK.
PvP wants a site plan
One entry, one flex, one support. Everyone lurking is how you lose the plant timer.
Learn two operators well. A deep pool of level 1 characters is a handicap.
Gadget timing
A smoke after your teammate already died is a funeral. Throw util as they swing, not as a reaction clip.
If you want extra reading after this guide, you can also open this handbook.