Game Mechanics: Players being invincible after zoning?

[Flowz]

invincible [ɪnˈvɪnsəbəl]
adj
1. incapable of being defeated; unconquerable
2. unable to be overcome; insuperable


in·vis·i·ble (n-vz-bl)
adj.
1. Impossible to see; not visible: Air is invisible.
2. Not accessible to view; hidden: mountain peaks invisible in the fog.
3. Not easily noticed or detected; inconspicuous: "The poor are politically invisible" (Michael Harrington).
4. Not published in financial statements