Does scaling/challenging require a weakened tower?

[Vyrotek]

A ROBOT has SCALED the TOWER if, at the conclusion of the MATCH, the ROBOT:
A. is in contact with a unique RUNG, and
B. has all of its BUMPERS fully above the height of the low GOALS.

A TOWER is CAPTURED if, at the conclusion of the MATCH:
A. the TOWER is WEAKENED, and
B. the TOWER is surrounded such that each of the three (3) opponent ROBOTS has
SCALED or CHALLENGED a unique face of the TOWER

The rules don't seem to indicate that you must weaken the tower in order to get points for scaling or challenging it. Is this the case?

[MichaelaLeung]

No, scaling and challenging can be done on an unweakened tower and the points still scored but you cannot capture an unweakened tower.

[lblight98]

As far as I can tell, capturing the tower takes all 3 bots around a tower that has no life left, but challenging and scaling seem to not require 0 life in the tower. WEAKENED is defined as "the state of a TOWER if its STRENGTH is at or below zero (0)", so the tower apparently should have to be at 0 (or less??) health to be a capture
Happy Building!