Bridge ally ways

Situation, I am blue alliance, I want to go into red alliances ally to snag some basket balls for scoring. Is that allowed or is it like last year and they are a restricted area.

You are allowed, however if you contact an opposing robot, (even if they run into you), you get a penalty.

Do you happen to know what rule that corresponds to?

[G28]
Robots may not touch an opponent Robot in contact with its Key, Alley, or Bridge.
Violation: Foul; Technical-Foul for purposeful, consequential contact.

This rule applied at all times, no matter who initiates the contact, see [G44].

Therefore, not having a defender would be a penalty to your team. You need to be able to bump the guys that get into your alley…