The Phantom 'Mech is the most prominent canonical allusion to a possibly supernatural event or power within the BattleTech universe. It remains somewhat enigmatic.
 The Phantom 'Mech incident on Mallory's World
The term Phantom 'Mech usually refers to the conclusion of the famous duel between Morgan Kell and Yorinaga Kurita on Mallory's World in 3016. The duel gained legendary status among MechWarriors throughout the Inner Sphere; accordingly, myths and half-truths abound and accounts of the event are usually of dubious veracity.
Forces from the Draconis Combine, including the elite 2nd Sword of Light Regiment, launched a major attack against the Federated Suns in 3013. On Mallory's World, First Prince Ian Davion fought a rearguard action when he was killed by Yorinaga Kurita, then a battalion commander in the Second Sword of Light. The Kell Hounds, a mercenary unit employed by the Federated Suns, moved in to allow the defenders to recover Prince Ian's body before the Kurita units could take it as a trophy. This, and their raid on Murchison a year later, earned the Kell Hounds the enmity of House Kurita.
Following the death of Ian Davion, Yorinaga Kurita was promoted to the rank of Tai-sa and was made overall commander of the 2nd Sword of Light, with free reins to oversee the battle on Mallory's World.
 The duel
At the beginning of the year 3016, the fighting on Mallory's World still raged on. In what had become a personal issue between himself and Morgan Kell, Yorinaga Kurita decided to crush the remaining Kell Hounds in order to demoralize the defenders. The entire Second Sword of Light regiment moved against the Kell Hounds, and before long had one battalion surrounded in their base.
In this hopeless situation, Morgan Kell stepped forward in his Archer and recounted the heroic deeds of his ancestors in Japanese, calling for a duel with a member of the 2nd Sword of Light. It obviously fell to the regiment's commander, Yorinaga Kurita, to answer the call; he stepped forward in his Warhammer and listed the deeds of his ancestors as well, in precise English. Although the combatants' respective BattleMech models meant that Kell was clearly disadvantaged at shorter ranges, he ignored his LRM-20 launchers and chose to engage the Warhammer at very short range in a direct match. There could be no doubt that he was offering his life for that of his men, and was going to sacrifice himself.
Yorinaga Kurita essentially defeated Morgan Kell in the fight. In the end, Kurita feigned the failure of his right PPC, then surprisingly used it to shoot off the Archer's right arm. Kell's critically damaged 'Mech toppled to its knees right in front of Kurita's Warhammer who then fired all weapons at Kell's Archer ("Alpha strike") at pointblank range, but miraculously missed with each and every weapon although Kell did not even move. Conversely, Kell fired his long-range missile launchers. The missiles failed to arm due to the very short range; their impact did crack open the canopy of Kurita's 'Mech, however. Kurita fired all his weapons once more, only to completely miss Kell again.
Kell did not return fire. Instead, he respectfully bowed to his opponent in his Archer, acknowledging him as the better warrior. The simple gesture meant that Kurita could not kill Kell without losing his honor now. Ashamed, Yorinaga Kurita uttered a haiku:
|“|| Yellow bird I see.
The gray dragon hides wisely.
Honor is duty.
He conceded victory to Morgan Kell and allowed the Kell Hounds to withdraw while he ordered his own troops to retreat. When the pilot of a Panther objected to the order, Yorinaga Kurita destroyed the 'Mech with a single concentrated blast of fire. While his warriors retreated, Kurita threw his katana and wakizashi (which he had received from Coordinator Takashi Kurita personally) from his cockpit.
The mysterious event has never been given a satisfactory explanation. Kurita later claimed that he had had the Archer plain in his sights at very short range, but then Kell's 'Mech had inexplicably disappeared from all sensors all of a sudden, despite standing still, and the salvo missed because the targeting computer could not acquire a lock. Similarly, Chu-sa Narimasa Asano, then a Marauder pilot with the Second Sword of Light, later recounted how the Archer had disappeared from all sensors despite being in plain sight.
The duel was a turning point for both Morgan Kell and Yorinaga Kurita.
The former largely disbanded the Kell Hounds down from a regiment to a single battalion and went into exile in a Christian monastery on Zaniah III without a word of explanation.
The latter requested permission from his Coordinator to commit seppuku, but the request was denied and he was exiled to a zen monastery on Echo V instead. From there, he issued the same request each year but received no answer until 1 January 3027 when he was recalled to active duty and tasked with the creation of a new elite unit, the Genyosha. After fulfilling this order, his death wish would be granted.
 Patrick Kell's last fight
By sheer coincidence, Morgan Kell's brother Patrick wound up leading the Kell Hounds in a battle against the Genyosha on Styx on 26 May, 3027. He piloted a Victor that disappeared from the targeting systems (as reported over the radio by Kell Hounds member Austin Brand and witnessed by Daniel Allard) in much the same fashion as Morgan Kell's Archer had on Mallory's World. Dan Allard's Valkyrie managed to acquire a transient IR signature of Patrick Kell's Victor for half a second when the Victor was hit by two PPCs from Kurita's Warhammer; the other Kurita 'Mechs inexplicably kept missing the Victor. During this fight, which was not a duel but a battle between several dozen 'Mechs, Yorinaga Kurita's Warhammer, too, could not be acquired as a target for some time while it closed with Patrick Kell's 'Mech. Dan Allard ultimately rammed his own 'Mech into the back of Kurita's machine, disabling both. Patrick Kell had already suffered mortal wounds from Yorinaga Kurita's Warhammer, however, and died shortly afterward.
 Final showdown
The return of Yorinaga Kurita brought Morgan Kell out of his self-imposed exile. He took command of the Kell Hounds again and quickly rebuilt them to regiment strength just prior to the Fourth Succession War. The Kell Hounds and the Draconis Combine, especially the Sword of Light regiments and the Genyosha, frequently attacked each others bases in attempts to force a final confrontation. Morgan Kell's Archer repeatedly proved impossible to lock on during these encounters. The final battle took place in October 3029 on Nusakan. The 5th Sword of Light had already engaged the Kell Hounds in intense one-to-one fighting when the Genyosha arrived.
Again, Yorinaga Kurita and Morgan Kell squared off in a one-on-one duel. It was a virtual replay of their fight on Mallory's World thirteen years earlier, only Morgan Kell did not fire a single shot this time while Kurita fired virtually everything he had. Kell's Archer (again) lost an arm and dropped to its knees before Kurita's Warhammer, then (again) stood and bowed to his opponent.
This time, Kurita could not return the gesture because the full salvo had overheated and immobilized his Warhammer in the Nusakan desert. By his own honor code, he had again lost the duel and he subsequently committed seppuku. Deeply impressed, Yorinaga Kurita's son Akira Brahe and a dozen other Genyosha MechWarriors turned their backs on the Draconis Combine on the spot and joined the Kell Hounds.
 Other instances
Two vaguely similar occurrences happened after 3029:
- During the Battle of Luthien in late 3051 Morgan Kell, again in an Archer, stood on a hill and directed the Kell Hounds' 1st Regiment against an assault by Clusters of Nova Cat BattleMechs. Again, despite making himself a perfect target for any number of advanced OmniMechs who tried their best to bring him down, the elite Clan Warriors were unable to land a hit on the mercenary.
- When Aidan Pryde fought a rearguard action to cover his Clan's withdrawal at the conclusion of the Battle of Tukayyid, his numerous foes seemed unable to hit him, although he was ultimately killed in that fight.
 Phantom 'Mech Ability?
In the (canonical) sourcebook, The Kell Hounds, a mystical ability called the "Phantom 'Mech Ability" (also known as "PMA") was postulated as the reason for the phenomenon. Both Morgan and Patrick Kell, as well as Yorinaga Kurita, allegedly possessed that ability. The Battle of Luthien Sourcebook likewise repeated a writeup for rules regarding this ability for Morgan Kell.
This sparked a controversy among fans of the BattleTech universe whether or not PMA is acceptable as canon; many feel that a mystical ability seems rather far-fetched, especially considering the technically oriented outlook of the BattleTech universe and the absence of any psi powers, magic, telepathy etc. otherwise.
The BattleTech Line Developer, Herbert A. Beas II, has since explicitly refuted the existence of such a mystical ability, expressly stating in an official verdict on the CBT Forum that "Magic" is among "Other things not BattleTech". He elaborated by saying that while some strange events happened in established canon, "most of these can be played off as near-death experiences and hallucinations".
In accordance with the Canon policy for BattleTech, this ruling retconned out the rules in the aforementioned sourcebooks and established that no supernatural ability was behind the events (which remain unexplained).
 ECM or Cloaking Device
The preferred alternative explanation for the Phantom 'Mech phenomenon is that the Kells used some kind of lostech ECM system, jammer or cloaking device such as the Chameleon Light Polarization Shield and/or Null Signature System. This assumption is supported by the fact that Morgan Kell was with Katrina Steiner when she disappeared into the Periphery for a year, returning in 3006 with valuable lostech devices including the "black box" superluminal fax machines.
The mysterious device may have been disabled or overloaded for the short period of time that Kell's Victor became visible on sensors following the twin PPC hits.
It could be argued that Yorinaga Kurita's Warhammer became impossible to lock on because it was affected by the proximity of Kell's Victor and its cloaking device.
- The duel is never described from an omniscient perspective; instead, it is recounted indirectly by various people in different sources. Since the duel has a legendary status within the universe, those statements by unreliable narrators are hardly objective, and may rather be blurring the subject.
- Critter-TEK parodies the Phantom 'Mech with a special rule called "The amazing Ghost TEK" ability, which "allows the Swell Hounds to rescue any important character or leader TEK from overwhelming odds or an desperate situation, once during a scenario."