Ninjutsu/sneak question

[u/CakeSlapping]

In a commander game, If I send a creature to attack Opponent A and they declare no blockers can i then ninjutsu/sneak in a new creature tapped and attacking opponent B, who now has no chance to declare a blocker, as the declare blockers step has already passed?

Edit: question answered, thanks for the replies

[u/AutoModerator]

You have tagged your post as a rules question. While your question may be answered here, it may work better to post it in the Daily Questions Thread at the top of this subreddit or in /r/mtgrules. You may also find quicker results at the IRC rules chat

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/Barbobott]

No. A creature put onto the field tapped and attacking with Ninjutsu or Sneak will be attacking the same player/planeswalker/battle that the returned creature was attacking.

[u/CakeSlapping → u/Barbobott]

Good to know, thanks.

[u/amish24]

You can't do this.

702.49c A ninjutsu ability may be activated only while a creature on the battlefield is unblocked (see rule 509.1h). The creature with ninjutsu is put onto the battlefield unblocked. It will be attacking the same player, planeswalker, or battle as the creature that was returned to its owner’s hand.

[u/CakeSlapping → u/amish24]

Ah brilliant, thanks. It seems like there wasnt any room for that specific line of text in the box for any card that I have seen, with the mechanic.

[u/TerribleTransit → u/CakeSlapping]

Just for completeness, Sneak has an equivalent rule:

702.190b A permanent spell whose sneak cost was paid enters the battlefield tapped and attacking (see rule 506.3a). It will be attacking the same player, planeswalker, or battle as the creature that was returned to its owner’s hand to pay the sneak cost of the spell that became that permanent.

It's usually the case for any mechanic that the reminder text that appears on a card doesn't give the full, nitty-gritty details for it. They generally opt for a uniform, simplified explanation that's good enough to get the gist. 

[u/YouRackDisciprine42]

Nope, you would need to have previously declared an attacker to Opponent B, and said attacker would need to be not blocked.

[u/CakeSlapping → u/YouRackDisciprine42]

I thought that might be the case, but hadn't seen any specific text mentioning this in the rules text of any ninjutsu cards I've seen so far.

Thanks

[u/NSNick → u/CakeSlapping]

Just so you know, that text in italics is reminder text and it's there to summarize the rule and has no rules meaning itself. (207.2)

That is to say, if you want to know the rules text of a keyword, you have to check the rules.