Rule 7.35 states:
Combat units may not melee/attack through unreached Wall or Tower hexsides, unless the attacking unit is using a Siege Tower or a Ladder of if the attacking unit is on a city level higher than the defending unit.
Rule 16.43 states:
In order to use Ladders to scale walls, a combat unit moves adjacent to the designated Wall (or Gate, etc.) hexside and places a Ladder Counter in that hex. On the following Game-Turn, units may use the Ladder to cross the Wall at a cost of 3 additional Movement Points.
Question: A unit has just placed a Ladder at the end of its movement. May it attack an enemy unit in a Tower (or on a higher level behind a Wall hexside) in that same Combat Phase? Or must the unit wait until the following Game-Turn to attack?
For movement purposes, the benefit of the ladder is not available until the following turn. Maybe play it the same for combat purposes?