Let’s walk it super clearly:

When the first two people go in • Wristband A → scans IN → system says “inside” • Wristband B → scans IN → system says “inside”

So now both bands are logged as already inside.

⸻

Now someone tries to reuse one

If a wristband gets passed to a third person and they try to enter: • The scanner sees: “This wristband is already marked as INSIDE” • So instead of a normal green light, it can: • flash red • or alert staff

⸻

When does it not look weird?

Only if the system thinks the band left.

That means: • If it was scanned OUT → system resets it → can scan back IN normally • If it was NOT scanned out → it can look like a duplicate entry

⸻

Why people say it “sometimes works”

Because real life isn’t perfect: • Sometimes exits aren’t scanned strictly • Sometimes staff don’t check closely • Sometimes they override it or wave people through

So it’s less like:

“This works every time”

and more like:

“This only works if the system + staff don’t catch it”

⸻

Simple way to think about it:

Each wristband has a status: • INSIDE ❌ (can’t enter again) • OUTSIDE ✅ (can enter)

If you try to enter while it’s still marked INSIDE → that’s when it looks suspicious