Any effect that would inflict damage to a player instead increases their Life Points by the same amount. When a card's effect to destroy a monster(s) on the field is activated, you can send 1 card from your hand to the Graveyard to negate its activation and destroy the card.
Rulings for Prime Material DragonYu-gi-oh! Card
"Prime Material Dragon's" first effect is a Continuous Effect.
While "Prime Material Dragon" is face-up on the field, if an effect would inflict damage to both players' Life Points, both players will gain Life Points instead.
If "The Immortal of Thunder" is sent to the Graveyard, its owner will lose 5000 Life Points because this is not damage. "Prime Material Dragon" cannot change it into a Life Point gain.
"Prime Material Dragon's" second effect can be activated during any Game Phase, including the Damage Step.
"Prime Material Dragon's" second effect works like "My Body as a Shield". "Prime Material Dragon" can negate cards such as "Smashing Ground", "Nobleman of Crossout", "Shield Crush", "Thousand Knives", "Trap Hole", "Mirror Force", "Ring of Destruction", "Torrential Tribute", "Bottomless Trap Hole", "Swarm of Scarabs", "Dark Armed Dragon", "Raigeki Break", "XYZ Dragon Cannon", "Mega-Ton Magical Cannon", "Exiled Force" (negates the effect but will not destroy "Exiled Force" as it is already in the Graveyard), "Soul Taker" (negates "Soul Taker" so you do not gain Life Points), "Jowgen the Spiritualist" (when its effect is activated), "Dragon's Gunfire" (if the effect that destroys a monster is selected), or "The Last Warrior From Another Planet" (negates the effect and destroys "The Last Warrior From Another Planet").
"Prime Material Dragon" can only be used against effects that will destroy monsters at that time. For example, you cannot use "Prime Material Dragon's" effect when "Dark Armed Dragon" is Special Summoned; you can only use it in response to the activation of "Dark Armed Dragon's" effect when it targets a monster. Also, you cannot use "Prime Material Dragon's" effect against cards whose effects will not destroy a monster right away, so you cannot use "Prime Material Dragon" against "Jigen Bakudan", "Ekibyo Drakmord", "Magical Hats", "Steel Scorpion", "Toon Monsters", "Thunder Nyan Nyan", "Gradius' Option", "Summoner of Illusions", "Limiter Removal", "Call of the Haunted", "Premature Burial", or "Arutonomous Action Unit".
You cannot use "Prime Material Dragon's" effect against cards whose effects may or may not destroy a monster right away, such as "Earthshaker", "Barrel Dragon", "Acid Trap Hole", or "Time Wizard".
You cannot use "Prime Material Dragon's" effect against monsters with continuous effects such as "Kotodama" .
You can activate the second effect of your "Prime Material Dragon" when your opponent activates the second effect of their "Prime Material Dragon".