502.22. Flashback
502.22a Flashback appears on some instants and sorceries. It represents two static abilities: one functions while the card is in a player’s graveyard and the other functions while the card is on the stack. “Flashback [cost]” means “You may play this card from your graveyard by paying [cost] rather than paying its mana cost” and “If the flashback cost was paid, remove this card from the game instead of putting it anywhere else any time it would leave the stack.” Playing a spell using its flashback ability follows the rules for paying alternative costs in rules 409.1b and 409.1f-h.
502.23. Threshold
502.23a Threshold used to be a keyword ability. It is now an ability word and has no rules meaning. All cards printed with the threshold keyword have received errata. Updated wordings are available in the Oracle card reference.
502.24. Madness
502.24a Madness is a keyword that represents two abilities. The first is a static ability that functions while the card with madness is in a player's hand. The second is a triggered ability that functions when the first ability is applied. “Madness [cost]” means “If a player would discard this card, that player discards it, but may remove it from the game instead of putting it into his or her graveyard” and “When this card is removed from the game this way, its owner may play it by paying [cost] rather than paying its mana cost. If that player doesn't, he or she puts this card into his or her graveyard.”
502.24b Playing a spell using its madness ability follows the rules for paying alternative costs in rules 409.1b and 409.1f-h.
502.25. Fear
502.25a Fear is an evasion ability.
502.25b A creature with fear can’t be blocked except by artifact creatures and/or black creatures. (See rule 309, “Declare Blockers Step.”)
502.25c Multiple instances of fear on the same creature are redundant.
502.26. Morph
502.26a Morph is a static ability that functions in any zone from which you could play the card it’s on, and the morph effect works any time the card is face down. “Morph [cost]” means “You may play this card as a 2/2 face-down creature, with no text, no name, no subtypes, no expansion symbol, and no mana cost by paying {3} rather than its mana cost.” Any time you could play an instant, you may show all players the morph cost for any face-down permanent you control, pay that cost, then turn the permanent face up. This action does not use the stack. (See rule 504, “Face-Down Spells and Permanents.”)
502.26b To play a card using its morph ability, turn it face down. It becomes a 2/2 face-down creature card, with no text, no name, no subtypes, no expansion symbol, and no mana cost. These values are the copiable values of that object’s characteristics. (See rule 418.5, “Interaction of Continuous Effects,” and rule 503, “Copying Objects.”) Put it onto the stack (as a face-down spell with the same characteristics), and pay {3} rather than pay its mana cost. This follows the rules for paying alternative costs. You can use morph to play a card from any zone from which you could normally play it. When the spell resolves, it comes into play with the same characteristics the spell had. The morph effect applies to the face-down object wherever it is, and it ends when the permanent is turned face up.
502.26c You can’t play a card face down if it doesn’t have morph.
502.26d Any time you could play an instant, you may turn a face-down permanent you control face up. To do this, show all players what the permanent’s morph cost will be when the effect ends, pay that cost, then turn the permanent face up. The morph effect on it ends, and it regains its normal characteristics. Any abilities relating to the permanent coming into play don’t trigger when it’s turned face up and don’t have any effect, because the permanent has already come into play.
502.26e If a face-up permanent is turned face down by a spell or ability, it becomes a 2/2 face-down creature, with no text, no name, no subtypes, no expansion symbol, and no mana cost. These values are the copiable values of that object’s characteristics. (See rule 418.5, “Interaction of Continuous Effects,” and rule 503, “Copying Objects.”) The rules for morph and face-down permanents apply to it normally.
502.26f See rule 504, “Face-Down Spells and Permanents,” for more information on how to play cards with morph.
502.27. Amplify
502.27a Amplify is a static ability. “Amplify N” means “As this object comes into play, reveal any number of cards from your hand that share a creature type with it. This permanent comes into play with N +1/+1 counters on it for each card revealed this way. You can’t reveal this card or any other cards that are coming into play at the same time as this card.”
502.27b If a creature has multiple instances of amplify, each one works separately.
502.28. Double Strike
502.28a Double strike is a static ability that modifies the rules for the combat damage step. (See rule 310, “Combat Damage Step.”)
502.28b At the start of the combat damage step, if at least one attacking or blocking creature has double strike or first strike, creatures without double strike or first strike (see rule 502.2, “First Strike”) don’t assign combat damage. Instead of proceeding to end of combat, the phase gets a second combat damage step to handle the remaining creatures. In the second combat damage step, surviving attackers and blockers that didn’t assign combat damage in the first step, plus any creatures with double strike, assign their combat damage.
502.28c Removing double strike from a creature during the first combat damage step will stop it from assigning combat damage in the second combat damage step.
502.28d Giving double strike to a creature with first strike after it has already put first strike combat damage onto the stack in the first combat damage step will allow the creature to assign combat damage in the second combat damage step.
502.28e Multiple instances of double strike on the same creature are redundant.
502.29. Provoke
502.29a Provoke is a triggered ability. “Provoke” means “Whenever this creature attacks, you may choose to have target creature defending player controls block this creature this combat if able. If you do, untap that creature.”
502.29b If a creature has multiple instances of provoke, each triggers separately.
502.30. Storm
502.30a Storm is a triggered ability that functions while the spell is on the stack. “Storm” means “When you play this spell, put a copy of it onto the stack for each other spell that was played before it this turn. If the spell has any targets, you may choose new targets for any number of the copies.”