Activate - Anytime a Magic or Trap card is played, it's considered activated. You cannot chain to a card effect that is not an activated effect. Certain continuous Magic and Trap cards can be activated even after they are active, while others cannot. If the card effect requires you to pay some sort of a cost to use the effect (such as Skull Lair), the card effect is considered to be activated and can be chained to. Continuous Magic/Trap effects that require you to pay for an attack in some way (such as Toll) are not considered activated effects, a player can't choose to use the effect. You cannot chain to the 500 damage you receive from effect of Toll when you attack. Continuous monster effects (such as Jinzo's and Muka Muka's) are not activated. Cost, trigger, multi-trigger, and flip effects are all activated effects and can be chained to as long as the timing is correct (during the damage step, you can't use cards that don't modify ATK/DEF).

Continuous - This can mean one of a few things. It either means a continuous Magic or Trap cards with the symbol, monster cards that have effects that are always active, but never activated (see Activate and Monster Effects), or any card that don't leave the field after it resolves. Once a card with a continuous effect leaves the field, the effect is no longer active. If you use Giant Trunade to return a Messenger of Peace to your hand, you can attack with your 1500 or more ATK monsters. If you chain a Typhoon to the activation of Imperial Order, the chain resolves and Imperial Order is destroyed before its effect can ever activate (see Chains).

Example:
Link 1: Raigeki
Link 2: Imperial Order
Link 3: Mystical Space Typhoon (Imperial Order selected)

resolving

Link 3: Imperial Order destroyed
Link 2: Because Imperial order is no longer on the field, it's effect cannot activate.
Link 1: Raigeki destroys all opponent's monsters on the field.

Controller/Control - Any card on your side of the is under your control, and is considered to be your monster as long as it remains on the field. If it is returned back to a players hand by a card effect, it goes to the player whose deck it originally came from. A card shifts control when it goes from one side of the field to the other. When a card shifts control, it is NOT flipped and does not change position, unless otherwise specified by the card. You may look at any card that is under your control without Flip Summoning it.

Cost - There are a lot of cards that require a coost to be activated. Costs include discarding a card, Tributing a monster from the field, sending Magic or Trap Cards to the graveyard, removing monsters from play, and paying Life Points. The cost is generally written in the form of Offer "that" to do "this," or Pay "this amount" to do "this," and it's usually the first thing written on the card. The cost is paid as soon as the card is activated, not when the chain resolves.

Example:
Link 1: Raigeki
Link 2: Magic Jammer - 1 card discarded from hand.
Link 3: Solemn Judgment - 1/2 the player's Life Points are paid

resolving

Link 3: Solemn Judgment negates and destroys Magic Jammer.
Link 2: Magic Jammer is negated, but the discarded card is not returned to the player's hand
Link 1: Raigki destroys all opponent's monsters.

Decrease - To lower the attack or defense of a monster, or to lower a player's Life Points. Cards such as Reverse Trap and Megamorph don't decrease a monster's ATK or DEF. Reverse Trap switches the effects of cards that increase and decrease ATK, so activating 2 at once is the same as activating just one. Megamorph can half a monster's original ATK. Because of that, it's not considered to "decrease" the ATK, but multiply it by 1/2. Card effects such as Reverse Trap don't affect Megamorph and cards similar to it.

Destroy - There is a huge difference between destroyy, send to the Graveyard, offer as Tribute, discard, and negate. There are 3 ways that cards can be destroyed. You can destroy a monster in battle, you can destroy a card by the effect of another card that specifically says it destroys a card, and non-continuous Magic and Trap cards are destroyed when they resolve. A monster used as a Tribute for a Tribute summon is not destroyed, it is simply Tributed. A monster sent to the Graveyard by the effect of Raigeki is considered destroyed, because Raigeki specifically states that it "Destroys all of your opponent's monsters on the field." A card sent to the Graveyard from your hand by Delinquent Duo is not considered destroyed, because cards sent from your hand to the Graveyard are simply considered discarded. Woodland Sprite does not destroy the Magic Card equipped to it because it states that you can send an Equip Magic Card equipped to it to the Graveyard to do damage, it doesn't state that you can destroy an Equip Magic Card equipped to it to do damage. If you chain a Mystical Space Typhoon to Raigeki to destroy it, the effect of Raigeki still happens because Mystical Space Typhoon only destroys the card, it doesn't negate the effect. You can use Mystical Typhoon to destroy a continuous card and the effect of the continuous card would no longer be active. You cannot destroy cards at will.

Example 1:
A player attacks with Blue-Eyes White Dragon and the opponent responds by activating Fairy Box. The attacking player chains Mystical Space Typhoon to Fairy Box.
Link 1: Fairy Box
Link 2: Mystical Space Typhoon (fairy box selected)
neither players add any more chain links

resolving

Link 2: Mystical Space Typhoon destroys Fairy Box
Link 1: The effect of Fairy Box is no longer activate on the field, and the coin is not flipped.

Example 2:
Player A has 5 cards in his/her Magic/Trap zones, and wishes to play a card from hand. He/she cannot choose to destroy his/her face-up Solemn Wishes or face-down Trap Hole unless another card effect allows him/her to. 

Discard - To send a card from your hand to the Graveeyard. You cannot discard cards at will. If you have a Monster Reborn and Barrel Dragon in your hand, you cannot discard the Barrel Dragon unless another card effect, such as Graceful Charity, allows or requires you to discard from your hand. If you have more than 6 cards during the End of your turn, you must discard cards from your hand until you have 6 left (no more, no less). If you have more than 6 cards in your hand at any other time, you do not discard any. (see also: Destroy, Random)

Double - When this refers to doubling a monster's AATK power, the ATK is not considered increased. Cards such as Megamorph and Limiter Removal that double or half a monster's ATK are considered multipliers.

Draw - Not to be confused with "pick up." You draaw a card during each Draw Phase, and whenever a card effect specifically states that you draw a card. The cards you pick up with Cyber Jar are not considered Draws. Card effects such as Appropriate refer to each time you draw cards, not to every card you draw. If you activate Pot of Greed when your opponent has Appropriate out, they only draw 2 cards, not 4.

Equip Magic Card - If the monster a Equip Magic Card targets is destroyed, the Equip Card is sent to the Graveyard (not destroyed). If the monster an Equip Magic Card targets is flipped face-down, the Equip Magic Card is sent to the Graveyard because it loses its target. If the monster stays face-up on the field and you destroy, return to hand, or send the Equip Magic Card to the Graveyard, the monster it was equipped to loses all effects of the Equip Card. If you illegally play an Equip Card on a monster, the Equip card returns to its original position.

Example: You play Invigoration from your hand onto a non-EARTH monster. Invigoration returns to your hand. If you flip it from the field to equip the non-EARTH monster, Invigoration is turned face-down onto the field where it originally was.

Field - A card is on the field if it's in one of tthe 5 monster zones, 5 Magic/Trap zones, or the Field Magic Card zone. Continuous effects are active only when the card is on the field (unless otherwise specified).

Flip - When a monster is turned face-up by an attack or a card effect. A monster that is flipped by an attack goes from face-down defense to face-up defense. Unless otherwise specified, a monster flipped by a card effect goes to face-up defense.

Flip Effect - A monster that has FLIP: written on it has a flip effect. A flip effect is the effect written right after FLIP:. It is activated when the monster is flipped or flip summoned.

Flip Summon - The act of manually flipping a monster from face-down to face-up attack. You can only Flip Summon a monster on your turn.  You cannot Flip Summon a monster on the same turn it was played face-down from your hand or Special Summoned by a card effect such as Spear Cretin.  A Flip Summon does not count as your one Normal Summon or Set per turn. When a monster is Flip Summoned, your opponent first has the opportunity to negate the summon and flip effect via Horn of Heaven or Solemn Judgment. If they do not, the monster is considered summoned and the effect is activated. Your opponent can then chain a card such as Torrential Tribute or Trap hole to the effect. The chain would resolve backwards. Torrential Tribute would destroy all monsters on the field, and then the flip effect would resolve.

Graveyard - Cards that are discarded, destroyed, Tribuuted etc. go to the Graveyard (unless otherwise specified).

Hand - Any card you draw or pick up with a card eeffect goes to your hand. There is no size limit for your hand, but if you have more than 6 cards in your hand at the end of your turn, you must discard cards until there are only 6 left.

Increase - To raise the attack or defense of a monsteer, or to raise a player's Life Points. Cards such as Reverse Trap and Megamorph don't increase a monster's ATK or DEF. Reverse Trap switches the effects of cards that increase and decrease ATK, so activating 2 at once is the same as activating just one. Megamorph can double a monster's original ATK. Because of that, it's not considered to "increase" the ATK, but multiply it by 2. Card effects such as Reverse Trap don't affect Megamorph and cards similar to it.

Monster Card Zone - Any of the five spaces on each side of the field that are for setting monsters. There are 10 total. Monsters must be set or summoned in one of these spaces, no where else.

Negate - There are 3 types of negation. There are cards that negate summons, cards that negate effects of monsters, magic, and trap, and there are cards that negate attacks. Something that is negated doesn't happen. The summon doesn't happen, the card effects don't happen, and the attack doesn't happen (however, all costs for doing the above 3 are still paid, see costs). The only cards that negate are the ones that specifically say that they negate something. Destroying a card does not negate the effect. However, destroying a continuous card can stop the effect (note the word stop, this is different than negate).

Normal Summon - To play a monster from your hand to the field in face-up attack position. You cannot Normal Summon a monster into defense position unless a card effect allows you to do so (Light of Intervention).  You are only allowed one Normal Summon or Set per turn.

Position - A card is generally in one of three different positions - face-up attack, face-down defense, and facce-up defense. On very rare occasion you can have a monster in face-down attack position. An attack position monster flipped face-down by Darkness Approaches is flipped to face-down attack position.

Random - If a card says to pick something at random, it must be randomly picked, no matter what. If you have a card that allows you to see your opponent's hand and you get to discard a random card in their hand via Don Zaloog etc., the hand is turned face-down and shuffled before the card is chosen.

Remove from Play - A card can only be removed from play due to the effect of itself or another card. When you remove a card from play, its generally a good idea to move the card to a pile either above the Graveyard or to the side of the Graveyard. You cannot revive a monster that is removed from play with Monster Reborn. If Fiber Jar is flipped, cards that are removed from play are not shuffled into your deck. Once the game is finished, the cards that were removed from play are shuffled back into you deck and can be used in the next game (they are not removed for the entire match).

Removed from the Field - When a card is sent from the field to the graveyard, returned to your hand, returned to your deck, or removed from play.

Reverse - Not to be confused for the Japanese version of FLIP. To reverse something does not mean that you put it back to normal. If you reverse a decrease in attack, it becomes an increase in attack. Cards that reverse effects do not stack. Using 2 Reverse Traps has the same effect as using 1. Having 2 Bad Reaction to Simouchi won't cause your opponent to lose 2000 Life Points from Snatch Steal.

Pick Up - Pick up and Draw are two entirely different things. When you pick up a card it does not go anywhere until the card that caused you to pick it up specifies where it goes. (Cards can go to the field, graveyard, hand, or out of play).

Select - Immediately after a card is activated, youu must select the card or cards required for the effect. When you play Monster Reborn, you must immediately select the Monster Card you want to revive. You don't wait until the chain resolves to decide. You must select the monsters you wish to take with Invader of the Throne when you Flip Summon it. When you flip Magician of Faith, you must select the Magic Card immediately. Creature Swap is an exception. The monsters are not selected until the effect resolves.

Example 1 (Monster Reborn vs Call of the Haunted)
Link 1: Monster Reborn - Jinzo selected from opponent's Graveyard
Link 2: Call of the Haunted - Opponent selects the same Jinzo

resolving

Link 2: Call of the Haunted revives Jinzo
Link 1: Monster Reborn has no effect because the card selected is no longer in the graveyard

Example 2 (Invader of the Throne vs Ring of Destruction)
Invader of the Throne is flip summoned and the opponent does not negate the summon.
Link 1: Invader of the Throne - Dark Magician chosen as the target
Link 2: Ring of Destruction - Dark Magician chosen as the target

resolving

Link 2: Ring of Destruction destroys Dark Magician and inflicts 2500 damage to both player's Life Points.
Link 1: The target of Invader of the Throne is no longer on the field, the effect fizzles. The player that flipped Invader of the Throne does not give it to the opponent, and cannot chose another target with the effect.

Example 3 (Graverobber vs Magician of Faith)
Magician of Faith is flip summoned and the opponent does not negate the summon.
Link 1: Magician of Faith - Dark Hole selected
Link 2: Graverobber chained to the effect of Magician - Dark Hole selected

resolving

Link 2: Dark Hole taken from the graveyard.
Link 1: Dark Hole is no longer in the graveyard, the effect of Magician of Faith fizzles.

Set - To put a monster from your hand onto the ffield in face-down defense position. You are only allowed to Set one monster in a turn, and cannot set a monster if you already Normal Summoned a monster in that turn.

Special Summon - You can Special Summon as many monsters in a turn as you wish. If you Special Summon a monster before you've Normal Summoned or Set a monster you may still Normal Summon or Set a monster in that turn. You don't have to Tribute for high level monsters such as Blue-Eyes White Dragon when they are Special Summoned. Card effects that have a Special Summon requirement (Toon monsters, Ritual monsters, Fusion monsters, monsters such as Gate Guardian, monsters such as Dark Necrofear etc.) cannot be Special Summoned from the Graveyard unless they were Special Summoned the way the card requires them to be summoned and later sent to the Graveyard. If those cards are returned to your hand or Deck and discarded in some way, you cannot Special Summon them via Monster Reborn etc. If they return to your hand, you still have to Special Summon them in the way written on the card (even though they were already summoned correctly). The Special Summon requirement for Toon Monsters is for Toon World to be on the field and for the correct number of monsters to be tributed. (You have to offer 2 monsters to Special Summon Blue-Eyes Toon Dragon, 1 to summon Toon Summoned Skull, and none to summon Toon mermaid) The Tributes are not considered Tributes for a Tribute Summon, so you can offer Scapegoat tokens.

Summon - Special Summoning or Normal Summoning are both methods of summoning. Setting a monster is not. A monster Special Summoned in face-down defense mode by Spear Cretin is still considered a Special Summon.

Tribute - A tribute is considered a cost. When you uuse a card as a Tribute for a Tribute summon or for a Tribute for a card effect, that card is immediately sent to the graveyard. It isn't sent to the Graveyard when the Summon is completed or the chain resolves. A Tribute for one card's effect or 1 monster's summon does not count for the Tribute of another card's effect or another monster's summon. Using Share the Pain does not allow you to automatically summon a high level monster.