Learn ygo effects

as of 2/19/2015, the time of writing this, this is the latest rulebook
http://www.yugioh-card.com/uk/rulebook/Rulebook_v9_en.pdf
Starting on page 9, it describes basically all of the effects below
And on page 40 it describes what chains are and how they work
It is recommended that you read the official rulebook before you read this as nothing is official, even though it is all accurate.


surely I don't have to explain a chain
it starts with an effect being activated as Chain Link (CL) 1, this is a Spell Speed 1 or 2 card
then spell speed 2 and 3 cards can be chained in response, as long as they can be activate.
A card can only be chained if it is equal or greater spell speed than the last card/effect activated
So if a chain goes like this
CL1 Card A, spell speed 1
CL2 Card B, spell speed 2
CL3 Card C, spell speed 2
CL4 Card D, spell speed 3
a spell speed 2 card cannot be chained to card D
And if nothing else is chained, then the chain resolves in reverse order, so like this
Card D
Card C
Card B
Card A

There are a few types of effects.
Ignition, continuous, quick, trigger, condition.
Also lingering, optional and mandatory/compulsory exist, but they're not their own type of effect.
Summons do not start chains.
I will only provide card text that is relevant to the effect discussion. So if a card has a quick effect and an ignition effect, and I'm talking about ignition effects, I will only provide text from the ignition part.
Also this only applies to cards with Problem Solving Card Text (PSCT), but only when reading the cards. Older cards still have these types of effects, but is sometimes harder to tell what is what, and how you can do a thing.

Optional effects say “You can” in them. Mandatory/compulsory effects do not say “you can”.
Only trigger/quick effects can be optional/mandatory.
Ignition effects are optional already. You do not have to activate them at all if you don't want to.

A Lingering Effect is any effect that applies even if the card is no longer on the field. Lingering effects cannot be negated (except by negating the initial effect).

Ignition, spell speed 1, has a colon of when you can activate it, and a semicolon of all costs
an example
“If this card is in your hand or Graveyard: You can banish a total of 2 FIRE and/or Dragon-Type monsters from your hand and/or Graveyard, except this card; Special Summon this card.”
"If you control another "Yosenju" monster: You can target 1 face-up card your opponent controls; return it to the hand."
This is ignition because it doesn't say when you can activate it, so can only be activated during M1.
In order to activate it, you need to be able to do everything before the semicolon, and met the requirements before the colon. When the effect resolves, everything after the semicolon, and colon in some cases is the actual effect.
Another example “Once per turn: You can detach 1 Xyz Material from this card and choose a number from 1 to 3, then send that many cards from the top of your Deck to the Graveyard; until the end of this turn, this card gains 500 ATK for each card sent to the Graveyard this way.”
Now that you know about ignition effects, you should be able to decipher this one.
But remember, if the monster has it's effect negated, the effect no longer applies.


Continuous effects, does not start a chain, constantly applying(typically the monster has to be face up), UNLESS they're negated by something.
"Neither player can Special Summon monsters."
As long as the monster with this effect is face up, neither player can special summon. Does not start a chain.


Quick effects, spell speed 2, can be activated like ignition effects, but during any phase, of any turn, so long as they meet the requirements.
"Once per turn, during either player's turn: You can detach 1 Xyz Material from this card; any card effects that activate in your opponent's Graveyard cannot be activated this turn."
Because it says "during either player's turn:" means it's a quick effect.
another example
"During your opponent's Main Phase, you can: Immediately after this effect resolves, Synchro Summon using this card you control (this is a Quick Effect)."
it's clear this is a quick effect because it says so


Trigger, spell speed 1, flip effects fall under here, and are usually compulsory/mandatory
most players say mandatory, but the official term is compulsory, but they mean the same thing
"When this card is flipped face-up: Destroy all Special Summoned monsters on the field."
this will start a new chain when flipped face up, then when it resolves it will "Destroy all Special Summoned monsters on the field."
optional trigger effects also exist
here are two examples
“If this card is banished: You can add 1 FIRE Dragon-Type monster from your Deck to your hand.”
"If this card is sent to the Graveyard: You can target 1 "Burning Abyss" card in your Graveyard, except this card; add it to your hand."
If everything before the colon happens, you can choose to activate the effect, in which you must do everything before the semicolon, then when it resolves, do what is after the semicolon.


Conditions exist, and do not start a chain. You simply cannot do what they say, or have to do what they say. They're similar to continuous, but cannot be negated.
here are some examples
"Cannot be used as a Synchro Material, except for the Synchro Summon of a Dragon-Type monster. The other Synchro Material(s) cannot be Level 4."
"You can only control 1 "Virgil, Rock Star of the Burning Abyss"."
"Cannot be Special Summoned, except by Pendulum Summon."
“You can only use 1 "Blaster, Dragon Ruler of Infernos" effect per turn, and only once that turn.”
“Cannot be Special Summoned.”
These are usually very clear, and cannot be negated.