Damage is a possibility to change the Lifepoints of a Player in a negative manner. You have to differenciate between two (2) types of damage:

If a monster controled by an opponent attacks you directly, you get Battle Damage according to the ATK-Points the attacking monster has.
If a monster controled by an opponent attacks one of your attack-position monsters, whichs ATK-Points are lower than the ATK-Points of the attacking monster, you getBattle Damage according to the difference between the ATK-Points.
Also you getBattle Damage if your attacking monster has lesser ATK-Points than the DEF-Points of an opponent monster in defense position.

Examples:

A "Dark Armed Dragon", controlled by your opponent, attacks your Lifepoints directly.

• 2800 Points of Battle Damage.

A "E-HERO Stratos", controlled by your opponent, attacks your "Spirit Reaper" in attack position.

• The difference ("Stratos": 1800ATK; "Spirit Reaper": 300ATK) is: 1500 Battle Damage.

A "Jinzo - Returner", controlled by your opponent, attacks your Lifepoints directly by using his effect.

• 600 Points of Battle Damage (THIS IS NO EFFECT DAMAGE!)

If you get your Lifepoints lowered through a card effect, not through battle with an opponent's monster, it is called Effect Damage.

Examples:

You activate the effect of your "Wave-Diffusion-Cannon", which is on the field since 8 of your Standby Phases.

• Your opponent gets 8000 Points of Effect Damage.

Your opponent tributes a DARKNESS Monster to activate the effect of "Shadow Priest of Ohm".

• You get 800 Points Effect Damage.

You activate 2 "Magical Explosion" as you have 20 Spell Cards in your Graveyard.

• Your opponent gets 4000 Points Effect Damage twice.

There are two different types of costs. Activation Costs and Maintaining Costs.
You pay costs at the moment you activate a card or an effect. If you play a card with activation costs, you will not get them back, even if the activation of this card gets negated. If you payed costs to activate a monster effect, you will not get them back.

You are never able to pay costs for an effect, if you do not have enough Life Points / Cards in your Hand / Monsters on the Field / ...
So you cannot defeat yourself by paying more Life Points than you acutally have. (This is a HUGE Difference to Damage!).

Costs and an effect do not have anything in common. There are monsters that are unaffected by Effects of Spell Cards, for Example. Also, there are Spell Cards that have Activation Costs of tributing a monster you control. It is possible to tribute a Monster that is unaffected by the Effect of Spell Cards, as it is send to the graveyard for the costs (which it is not protected by its effect). It is only protected by the effect of spell cards.

You can recognize new Cards with Activation Costs by the "semicolon -> ;" in your effect text.

• "Pay 1000 Life Points; Destroy..."
• "Discard 1 card to the graveyard; Draw..."

Activation Costs are paid in the moment of the cards activation. As already said, you cannot play a card you cannot afford the Activation Costs. Examples:

You only have 1000 Life Points left and you want to play "Instant Fusion".

• You cannot activate Instant Fusion.

You activate "Instant Fusion", which gets negated by your opponents "Solemn Judgment".

• You have to pay 1000 Life Points at the cards activation.

You control a face-up "Spell Economics".

• You do not have to pay Life Points to activate a Spell Card.
• You can activate Instant Fusion, although your Life Points are lower than 1000.

You want to activate the Effect of "Snipe Hunter".

• You must discard one card from your hand to activate its effect.

You want to activate the effect of "Snipe Hunter" a second time in the same turn.

• If you can discard a second card from your hand to the graveyard, you can activate the Effect of Snipe Hunter again, because it does not say "Once per turn".

Maintaining Costs cannot - as Activation Costs - get negated. Maintaining Costs usually have to be paid every round, so the card stays on the field. If you cannot pay the Maintaining Costs of a card, it normally gets destroyed and is sent to the graveyard.
The Maintaining Costs are written in the cards effect text. It tells you what you have to do each round, so the card stays on the field.

Examples:

You control a face-up "Koa'ki Meiru" Monster and your opponent controls a face-up "Destiny HERO - Plasma".

• You still have to pay the Maintaining Costs. So you have to discard a "Iron Core of Koa'ki Meiru" or show a Monster of the corresponding type. Otherwise your monster gets destroyed, although "Destiny HERO - Plasma" is face-up on the field.

There is a face-up "Jinzo" on the field and on you control a face-up "Mirror Wall".

• You still have to pay the 2000 Points of Life in each Standby Phase for "Mirror Wall", although there is a face-up Jinzo on the field.

There is a face-up "Skill Drain" on the field and you control a face-up "Terrorking Archfiend".

• You still have to pay 800 Life Points each Standby Phase. This is not negated by "Skill Drain".

There is a face-up Pandemonium on the field.

• You do not have to pay the Maintaining Costs for "Archfiend" - Monsters.
• Even if you only have 100 Life Points left, your "Archfiend" - Monsters stay on the field.

Each time, a card gets from game into the graveyard, it is sent to the graveyard. To destroy or tribute a card is not the same as a card, which got sent to the graveyard.
A card can be sent to the graveyard without getting destroyed or having been offered as a tribute.

If a card has an effect that activates as it gets destroyed, the effect DOES NOT activate, if the card is sent to the graveyard, without getting destroyed earlier.
If a card has an effect that activates as the card is offered as a tribute, the effect DOES NOT activate, if the card is sent to the graveyard, without getting offered as a tribute earlier.
You see, you only have to stick to the card text.

Example:

You control a face-up "Cyber Draon", equipped with "Premature Burial". Your opponent activates during your turn "Mystical Space-Typhoon", to destroy your "Premature Burial". You chain your face-down "Emergency Provisions" and send your "Premature Burial" as a cost to the graveyard.

• "Cyber Dragon" does not get destroyed through the effect of "Premature Burial", as "Premature Burial" was sent to the graveyard without getting destroyed.

A normal Spell or Trap card is declared as 'destroyed' after it is activated, but it can still be the target of other effects, that destroy. An effect, which sends a card back to the hand, can never regard a card that is already declared as destroyed. All cards on a chain remain on the field until the chain has completely resolved. The only exception is a card, that gets destroyed by another cards effect.

The Difference: If a card gets destroyed during a chain by another cards effect, it is sent to the graveyard immediately! (Even during resolution of a single link on the chain!)
If a card is sent to the graveyard (as it was a spell or trap card activated), it happens at the same time with all other cards involved in the chain, AFTER the complete chain has resolved.
In the chapter 'Chains' are examples, that describe the case of cards, getting sent to the graveyard during the resolving of a chain.

Another difference appears with the "Dark World" monsters, as they can activate their effect only, if they get discarded to the graveyard explicitly by a cards effect, for example by Morphing Jar.
Only sending a card to the graveyard would not activate the effect of Dark World Monsters, as sending is not the same as discarding. A card sending cards would be "The Creator".
Also, discarding as a cost does not activate the effect of a Dark World Monsters, as these costs are NOT a card effect. Dark World Monster have to get discarded by effect.

Examples:

"Goldd, Wu-Lord of the Dark World" gets discarded to the graveyard by "Card Destruction".

• As "Goldd, Wu-Lord of the Dark World" was sent through a card effect, its effect activates.

To cover the costs of "Lightning Vortex", "Goldd, Wu-Lord of the Dark World" gets discarded to the graveyard.

• "Goldd, Wu-Lord of the Dark World" gets discarded to the graveyard, but as this is not a cards effect, "Goldd, Wu-Lord of the Dark World" does not activate its effect. Remember, costs are not part of the cards effect and thus cannot be negated.

"Hand Destruction" is activated and during resolution of the effect a Player sends "Goldd, Wu-Lord of the Dark World" to the Graveyard.

• Also in this case, "Goldd, Wu-Lord of the Dark World" does not activate. This time it was a cards effect, getting "Goldd, Wu-Lord of the Dark World" to the graveyard, but it was send, not discarded.

If a card gets destroyed, it is normally sent to the graveyard. But not every card sent to the graveyard has to get destroyed beforehand. Most of the card texts are precise about the destruction of a card. If a card sends another card to the graveyard, it is not always mentioned precisely in the cards text. To get the difference, there is an example:

The effect text of "Card Trooper" says, that it has to be destroyed, to activate its effect. If it is offered as a tribute or sent to the graveyard, its effect does not activate.

Examples:

"Card Trooper" is sent to the graveyard by the effect of "Sky Scourge Nohrellas".

• As "Sky Scourge Nohrellas" does not destroy, the effect of "Card Trooper" does not activate.

To summon "Jinzo", "Card Trooper" was offered as a tribute and sent to the graveyard.

• As a Tribute does not count as 'destroyed', the effect of Card Trooper does not activate.

If a card is banished, it always happens face-up! (Exception: The card text says differently)
A face-up card that is banished, can always get back into the game through another cards effect.
All face-up cards that are banished can be seen by each player, this corresponds with the graveyard.

Example:

A monster in the graveyard of a Player gets banished by the effect of "Basu Souleater" and the player has a face-down "Return from a Different Dimension".

• As "Basu Souleater" does not say to banish a card face-down, the Monster gets banished face-up.
• A face-up banished Monster can be summoned by the effect of "Return from a Different Dimension".

Some cards banish cards face-down. A face-down banished card can only get back into play through another card, if the other card does not specify the cards type OR does say that it can also target a face-down banished card.

So with Primal Seed a face-down banished card can get back into the game, as Primal Seed does not specify which kind of a card and this is also told in the effect text. Return from the Different Dimension for example cannot get back a face-down banished card, as the face-down banished card cannot be declared clearly as a monster.

A face-down banished card cannot (!) be seen by an opponent.

Example:

A monster was banished face-down by the effect of "Dimension Capsule". The Player has "Return from a Different Dimension" face-down on his side of the field.

• The card is banished face-down, as "Dimension Capsule"s text says so.
• A face-down banished Monster cannot return trough "Return from the Different Dimension", as "Return from the Different Dimension" says that only Monsters can get back into play via a Special Summon.

An opponents monster is face-down on the field and you have "Nobleman of Crossout" on your hand.

• If "Nobleman of Crossout" targets the face-down monster, the monster is destroyed and banished FACE-UP! Because "Nobleman of Crossout" does not explicitly say, that the monster is banished face-down.
• The Monster banished that way could be summoned with "Return from a Different Dimension".

It is not important if a card is face-down while another card banishs it. The banished card will only be banished face-down, if the effect says so.

Considering targeting effects, we have to clearly distinguish between the effects of Monsters and Spell and Trap cards. At monster effects it is quite easy: If you can freely choose the target(s) at activition, it is a targeting effect. With Spell and Trap cards it is nearly the same. BUT effects that clearly say, which cards are affected, even if the effect text does not prescribe to choose a specific card.

Examples:

There are two monsters on the side of Player B. Player A flipps "Ryko, Lightsworn Hunter".

• Player A may choose either Monster on the field as the target for the effect of "Ryko, Lightsworn Hunter".
• Therefor "Ryko, Lightsworn Hunter" has only 1 designated target.

After Player A attacks, Player B activates a "Sakuretsu Armor".

• As the target is designated at activition (the 1 attacking monster) this effect targets.

Some effects target various monsters. But it still is the same as above: if you can freely choose the targets of those effects, and they are determined at activition, this effect is a targeting one.

Example:

Player A offeres "Treeborn Frog" as a tribute to summon "Mobius the Frost Monarch".

• The optional Triggereffect of "Mobius the Frost Monarch" can be activated, as he was properly summoned via a tribute summon.
• Player A may therefor choose up to two Spell and Trap cards, to destroy them.
• As Player A may choose freely, this effect targets.

Important: 'ALL Monsters on the field' or 'ALL Monsters of the following type' ... (e.g. Dragon) are not defined targets! A card with designated targets always targets on a given amount of cards (exactly 1, 2, 3, 4, etc)

Some cards are difficult to see, if they have a designated target. For their effects can not "A monster" be chosen, but just "a specific monster". These cards also are cards with a designated target.

Important:

Player A summons "Cyber Phoenix", Player B has a face-down "Trap Hole".

• As only one monster can be normal summoned at a time, "Trap Hole" can only designate one Monster as a target.
• Therefor "Trap Hole" targets.
• "Cyber Phoenix" negates Effects of Spell and Trap cards, targeting him, so "Trap Hole" is negated by "Cyber Phoenix".

These effects often are very easy to distinguish. If an effect does not contain any of the properties, a targeting effect has - it does not targe.

Player A activates "Smashing Ground". Player B has 3 face-up monsters on the field.

• Player A can not freely choose, which monster he wants to destroy, but "Smashing Ground" is like a homing missile, looking for its own 'target'. (The monster with highest DEF.)
• So "Smashing Ground" does not target.

Player A controls "Cyber Phoenix". Player B activates "Lightning Vortex".

• "Lightning Vortex" afflicts all face-up monsters.
• Therefor "Lightning Vortex" DOES NOT target, because a specific target would only be given if ONE, TWO, THREE or FOUR monsters would be afflicted, and not ALL MONSTERS.
• "Lightning Vortex" therefor destroys all machine-type monsters, which cannot be negated by "Cyber Phoenix".

Some effects may pertain various cards or only one, depending on the situation. Such cards are not designating a target. So they do not target.

Examples:

Player A activates "Return from a Different Dimension" and summons 3 Monsters to his side of the field. Player B controls a face-down "Bottomless Trap Hole".

• If player B activates "Bottomless Trap Hole", all monsters summoned with 1500 ATK or more will be banished.
• "Bottomless Trap Hole" does not have a clearly designated target, as shown in this example, as various monsters can be summoned at once.

Player A summons "Tyrant Dragon", Player B wants to react with "Bottomless Trap Hole" to the summon.

• The effect of "Bottomless Trap Hole" does not designate a target (look at the example mentioned before).
• So "Tyrant Dragon" will not negate "Bottomless Trap Hole" and he will be banished.

A difference is, if it is the free choice of a Player, if he wants to target one or more Monsters. If a player can choose freely up to X targets, so this effect is a targeting one.
As an example we could use "Mobius the Frost Monarch" or "Kuraz the Light Monarch".
Also, effects, that designate their targets at the resolve of the card, do not target!

Example:

Player A controls a face-up "Spirit Reaper", Player B controls a face-down monster. Player A activates "Creature Swap".

• The monsters for "Creature Swap" are decided during resolution of the effect of the card.
• Player B could possibly use "Scapegoat", as this card would resolve first (Chain!) and summon 4 monstertoken. So Player B could use one of the Tokens for the resolution of "Creature Swap".
• If none of the players wants to chain, during resolution of the cards effect only "Spirit Reaper" and the face-down monster would be on the field and therefor control would be changed with those two.
• "Spirit Reaper" would not destroy itself, as it was not targeted by a cards effect.

A card that targets can only be activated, if there is a target for it on the field, graveyard, ... But as we learn in the Chaper "Chains", there can be chained to the effect, there might be no fitting card left, as many things can happen. If one of the designated targets is no longer on the field (in the graveyard, ..) during the resolving of a cards effect, the card will try to resolve the other parts of the effect (as much as is possible).
If ALL targets of an effect vanish before resolution, the effect "fizzles".

Examples:

Player A wants to attack the Life Points of Player B directly. Player B activates "Magic Cylinder", Player A chains "Book of Moon".

• "Magic Cylinder" could be activated, as ist activation conditions were fulfilled and it had a valid target.
• After "Book of Moon" resolved, "Magic Cylinder" resolves, but it has no valid target anymore.
• Therefor "Magic Cylinder" resolve without effect.

Player A activates "Call of the Haunted" and targets his "Cyber Dragon" in the graveyard. Player B chains "D. D. Crow" and also targets "Cyber Dragon".

• As "D. D. Crow" will resolve first (Chain!), "Cyber Dragon" will be banished.
• As "Cyber Dragon" was banished, "Call of the Haunted" lacks its target.
• "Call of the Haunted" does not have any effect (fizzles) and remains on the field, useless.

As we see, a designated target is chosen by the activation of a card and cannot be changed afterwards.

Player A summons "Kuraz the Light Monarch" and designates his "Sangan" and a face-down Trap Card (Player B's Trap card) as his targets. Player B chains the face-down "Torrential Tribute".

• As "Torrential Tribute" resolves first, it destroys all monsters on the field.
• As "Kuraz the Light Monarch" resolves, there is one Target left, so the effect resolves as far as possible and Player B draws a card, after the effect of "Kuraz the Light Monarch" destroyed "Torrential Tribute".

Player A activates "Book of Life" and targets "Zombie Master" in his graveyard and "Treeborn Frog" in the Graceyard of his opponent. Player B chains "D. D. Crow" and targets "Zombie Master".

• As "D. D. Crow" resolves first, "Zombie Master" is banished.
• Afterwards "Book of Life" tries to resolve as much as possible and "Treeborn Frog" is banished.

Not every card, that gets from the Deck to the Hand of a Player is automatically 'drawn'. It can differ from 'pick up', 'add' or 'draw'. Which one is the case? Normally that is displayed in the cards effect text.

Examples:

A Player activates "Pot of Greed".

• This player draws (!) two cards.

Player A flipps "Cristal Seer" and there is a face-up Solemn Wishes is on the field.

• The player takes two cards and looks at them, than he adds (!) it to his hand. (This is NO draw.)
• The Player does not gain Life Points through the effect of "Solemn Wishes", as he did not draw a card.

A Player activates "Reasoning".

• The Player picks up (!) cards, until he has a appropriate Monster and special summons it, if possible. (This is no draw, the cards do NOT go to the hand either.)

A Player activates "Reinforcement of the Army".

• The Player adds (!) the card to his hand. (He does not pick up, nor does he draw.)

If cards are picked up or added to the hand, they do not count as 'drawn'. Normally: cards coming from the middle of the deck are never drawn!

Example:

Player A's "Sangan" is sent to the Graveyard.

• Player A picks up a Monster from his Deck. This does not count as drawn!

A picked-up card is never considered as it is "on the hand" of a player.

Example:

A face-up active "A Legendary Ocean" is on the field. "Morphing Jar #2" is flipped.

• If a monster with the Attribute Water and Level 5 is picked up, he cannot special summon the Monster as the effect of "A Legendary Ocean" does only consider cards on the field and in the hand. But it does not consider cards that are 'picked-up', as they are not on the hand (yet).

If a cards effect lets you pick up cards and you do not have any relevant card in your deck, you would pick up your entire deck. As this is not considered 'cards drawn', there is no possibilty to be 'out of deck' and die of it.

Example:

You activate "Monster Gate" and after you picked up your entire Deck you notice that there is no Monster left in your deck.

• As the cards were only 'picked up', you shuffle them and put them back into your Deck Zone.