The closest thing I can think of is the peculiar practice of the Krypteia in Ancient Sparta. Partly a training exercise in stealth for promising candidates in the Spartan military, and partly state terrorism aimed at the culling and cowing of their servile Helot population, the Krypteia occurred annually.

Any "Kryptes" chosen for this unique privilege were absolved of the crimes of murder (as the Ephors, an important component of the Spartan leadership, would declare war upon the Helots).

They'd be left on a secluded part of the wilderness without supplies, and expected to sustain themselves off the land and by resources acquired (stolen? plundered?) from Helots. However, the avoidance of detection or capture were paramount. Failure meant lashes at the least. (And I imagine possibly death at the hands of a resistant Helot, but no one really talks about that)

The specifics of their rules of engagement are muddy. Yet it's reasonable to presume there were firm limitations of some sort (likely a small recruitment pool, for example), because an annual wholesale slaughter of the healthiest Helots every Autumn/Winter would've undermined their economy.

The pragmatic goals of this training may have been oriented towards producing self-reliant commando or pathfinder units who could operate independent of the Hoplite formations. Another goal was to assay candidates, to find the best of the best. Only Spartan youth who'd succeeded in Krypteia were known as willing to kill for the state from a young age; therefore, as proven loyalists, were eligible for future leadership positions.

But bear in mind that there's a peculiar dearth of information on the Krypteia in spite of its frequency. Much of what's known comes from Plutarch who was not a contemporary; and aside from, for example, brief mentions here and there by Plato and others closer to the time, a fair bit of it's reasonable conjecture bounced between historians.

Sorry for asking this, but what is 'the Purge'?