2023-11-10 : "Discover N" means "Exile cards from the top of your library until you exile a nonland card with mana value N or less. That card is the "discovered" card. You may cast that card without paying its mana cost if the resulting spell's mana value is less than or equal to N. If you don't cast it, put that card into your hand. Put the remaining exiled cards on the bottom of your library in a random order."

2023-11-10 : A spell's mana value is determined only by its mana cost. Ignore any alternative costs, additional costs, cost increases, or cost reductions.

2023-11-10 : Effects that modify a creature's power and/or toughness, such as the ones created by Giant Growth, will apply to the creature no matter when they started to take effect. The same is true for any counters that change its power and/or toughness and effects that switch power and toughness.

2023-11-10 : If the artifact was already a creature, its base power and toughness will become 5/4. This overwrites any previous effects that set the creature's base power and toughness to specific values. Any power- or toughness-setting effects that start to apply after Zoetic Glyph becomes attached to the artifact will overwrite this effect.

2023-11-10 : If the creature Zoetic Glyph would enchant is an illegal target as Zoetic Glyph tries to resolve, it won't resolve. It's put into your graveyard from the stack, not the battlefield, so its last ability won't trigger.

2023-11-10 : If the discovered card has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

2023-11-10 : If you can't cast the discovered card (perhaps because there are no legal targets for the spell), you'll put it into your hand.

2023-11-10 : If you cast a spell "without paying its mana cost", you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the spell has any mandatory additional costs, you must pay those to cast it.

2023-11-10 : If you discover an adventurer card, split card, or modal double-faced card, you might be able to cast that card with either set of characteristics depending on the effect's discover value. For example, if you discover 4 and reveal Galvanic Giant (an adventurer card from Wilds of Eldraine with a mana value of 4), you could cast Galvanic Giant, but not Storm Reading (its Adventure, which has a mana value of 7). If you discover 7 and reveal Galvanic Giant, you could cast either Galvanic Giant or Storm Reading.

2023-11-10 : Some spells and abilities that cause you to discover may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won't resolve and you won't discover.

2023-11-10 : The artifact retains any types, subtypes, or supertypes it has. Notably, an Equipment that becomes an artifact creature usually can't be attached to another creature. If it was attached to a creature, it becomes unattached.

2023-11-10 : The mana value of a split card is determined by the combined mana cost of its two halves. If discover allows you to cast a split card, you may cast either half (as long as its mana value is less than or equal to the effect's discover value) but not both halves.

2023-11-10 : The resulting artifact creature will be able to attack on your turn if it's been under your control continuously since the turn began. That is, it doesn't matter how long it's been a creature, just how long it's been on the battlefield.

2023-11-10 : When you discover, you must exile cards. The only optional part of the ability is whether you cast the exiled card or put it into your hand.

2023-11-10 : You exile the cards face up. All players will be able to see them.