DiscardTo discard a card, move it from its owner’s hand to that player’s graveyard.
By default, effects that cause a player to discard a card allow the affected player to choose which card to discard. Some effects, however, require a random discard or allow another player to choose which card is discarded.
If a card is discarded, but an effect causes it to be put into a hidden zone instead of into its owner’s graveyard without being revealed, all values of that card’s characteristics are considered to be undefined. If a card is discarded this way to pay a cost that specifies a characteristic about the discarded card, that cost payment is illegal; the game returns to the moment before the cost was paid (see rule 733, “Handling Illegal Actions”). (CR 701.9) a card:
RegenerateIf the effect of a resolving spell or ability regenerates a permanent, it creates a replacement effect that protects the permanent the next time it would be destroyed this turn. In this case, “Regenerate [permanent]” means “The next time [permanent] would be destroyed this turn, instead remove all damage marked on it and its controller taps it. If it’s an attacking or blocking creature, remove it from combat.”
If the effect of a static ability regenerates a permanent, it replaces destruction with an alternate effect each time that permanent would be destroyed. In this case, “Regenerate [permanent]” means “Instead remove all damage marked on [permanent] and its controller taps it. If it’s an attacking or blocking creature, remove it from combat.”
Neither activating an ability that creates a regeneration shield nor casting a spell that creates a regeneration shield is the same as regenerating a permanent. Effects that say that a permanent can’t be regenerated don’t preclude such abilities from being activated or such spells from being cast; rather, they cause regeneration shields to not be applied. (CR 701.19) this creature. (The next time this creature would be destroyed this turn, instead
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) it, remove it from combat, and
healTo heal damage already dealt to a permanent, remove that marked damage from that permanent. If an effect states that damage already dealt to a permanent “is healed,” that permanent’s controller removes all marked damage from that permanent. (CR 701.69) all damage on it.)