magic jammer on battle phase

[dadejay]

my opponent attack me, i use scapegoat, can he use magic jammer to block it?

 

[babyarm]

Yes he can.

 

[Lord Hades]

...yes, you can activate any trap card in any phase except the ones that you can only activated in a especific situation...

 

[Digital Jedi]

Well not ANY Phase. You cannot activate certain cards in the Damage Step except Spell Speeds 2+ that specifically modify ATK or DEF and Counter Traps. There are a few exception to that rule but those situations are rare. Of course, Magic Jammer is a Counter Trap and can be used to negate a spell that can also be activated in the Damge Step. Like Limiter Removal fo example. Scapgoat cannot be activated in the Damage Step but the Battle Phase is just fine and therefore negatable by Magic Jammer.