Every type of card effect has a Spell Speed between 1 and 3. If you
want to respond to a card effect in a Chain, you have to use an effect
with Spell Speed 2 or higher, and it cannot have a lower Spell Speed
than the effect you are responding to.
Spell Speed 1:
Spells (Normal, Equip, Continuous, Field, Ritual),
Effect Monster’s effects (Ignition, Trigger, and Flip)
This is the slowest of all Spell Speeds. These cards cannot be
activated in response to any other effects. Typically, these effects
cannot be Chain Link 2 or higher, unless multiple Spell Speed 1
effects are activated simultaneously.
Spell Speed 2:
Traps (Normal, Continuous), Quick-Play Spells,
Effect Monster’s Quick Effects
These cards can be used to respond to a Spell Speed 1 or 2 effect,
and can typically be activated during any phase.
Spell Speed 3:
Counter Trap
This is the fastest of all Spell Speeds and can be used to respond to
a card of any Spell Speed. Only another Spell Speed 3 card may be
used to respond to these cards.