This card can only be activated when both players have 2 monsters or less on their respective sides of the field. Both players can only Normal Summon up to 2 additional monsters on their sides of the field.
Rulings
Individual Card FAQs
"Narrow Pass" can only be activated when Player A has 2 or fewer monsters and Player B has 2 or fewer monsters. So if there are 3 monsters in play (2 controlled by A and 1 by B) you can activate "Narrow Pass". But if either player controls 3 or more monsters on his side of the field then you cannot activate this card.
Once "Narrow Pass" is activate, as long as it remains face-up on the field, Player A can Normal Summon or Set 2 up to 2 additional monsters, and Player B can Normal Summon or Set up to 2 additional monsters. It is helpful to place counters on "Narrow Pass" to keep track.
If "Narrow Pass" is activate, and a player Normal Summons his 2 permitted monsters afterwards, if 1 of those is destroyed then he cannot replace it with another Normal Summon. Each player gets 2 additional Normal Summons or Sets, no matter what happens to those monsters afterwards.
"Narrow Pass" does not restrict Special Summons or Flip Summons.
Netrep Rulings
Narrow Pass can only be activated when Player A has 2 or fewer monsters and Player B has 2 or fewer monsters. So if there are 3 monsters in play (2 controlled by A and 1 by B) you can activate Narrow Pass. But if either player controls 3 or more monsters by himself then you cannot activate this card.
Once Narrow Pass is activated, as long as it remains face-up on the field, Player A can Normal Summon or Set 2 up to 2 additional monsters, and Player B can Normal Summon or Set up to 2 additional monsters. It is helpful to place counters on Narrow Pass to keep track.
If Narrow Pass is activated, and I Normal Summon my 2 monsters afterwards, if 1 of those is destroyed then I cannot "replace" it with another Normal Summon. Narrow Pass does not restrict Special Summons or Flip Summons.
Trap|
Continuous