Martin Marietta answered a hostile bid by launching its own tender offer for the raider

In August 1982 Bendix Corporation's chairman William Agee launched a hostile tender offer for Martin Marietta, aiming to buy a controlling stake in the smaller aerospace firm. Martin Marietta had already spurned merger talks and had no friendly acquirer waiting in the wings, while Bendix arrived with cash committed and the market's expectation that Martin Marietta would either fold or scramble for a rescue buyer.

Litigating to slow the tender offer, or racing to find a white knight while the stock was under siege, both would take months Martin Marietta didn't have. Simply refusing to sell wouldn't stop a majority of shareholders from tendering into Bendix's offer, and raising its own defenses financially risked bankrupting the company before the bid was even resolved.

Martin Marietta borrowed over a billion dollars and launched its own tender offer to buy Bendix stock, using the identical hostile-takeover mechanism Bendix was using against it - so that each company was simultaneously trying to buy control of the other, a maneuver reporters immediately dubbed the 'Pac-Man defense.'

Borrowed over a billion dollars and launched its own tender offer for Bendix, mirroring the hostile mechanism so each tried to buy the other—mutual assured destruction.

Counter-tendering forces the attacker to split attention and cash defending its own shares instead of only pressing the attack.

It creates mutual assured destruction that a third party typically has to step in and resolve.

The maneuver converts a one-sided assault into a standoff neither side can win alone.

When attacked with a takeover mechanism, consider using the same mechanism against the attacker, forcing them to defend and often drawing in a third party to resolve the standoff.

Bendix owned ~70% of Martin Marietta, which owned over half of Bendix; Allied Corp bought Bendix, and Martin Marietta stayed independent. The fight cemented 'Pac-Man defense' as a permanent term in takeover law and business schools, cost William Agee his chairmanship once Allied absorbed Bendix, and pushed corporate boards toward less mutually destructive defenses like the poison pill in the years that followed.