Corvus

A corvus is a boarding device that features a hinged counterweight system for mounting a bridge vertically on a siege tower or a vehicle, with a hooked end to grab onto a target vehicle or structure. A corvus is usually 10 feet wide and 15 feet long. It has a hardness of 5 and 10 hit points per square. Using a corvus requires a DC 10 Profession (siege engineer) check as a full-round action; if the check fails, the corvus fails to catch on the target and must be reset (a full-round action). A corvus mounted on a vehicle can target another moving vehicle (see Chapter 4: Vehicles). Doing so requires an opposed driving check to get the corvus into the correct position, which is within the length of the corvus and adjacent to the other vehicle. Once a corvus is attached, it takes a Strength check as a full-round action to dislodge the corvus. Alternatively, if the corvus is attached to a vehicle, either vehicle driver can make a driving check as a standard action to dislodge the corvus (a check that succeeds by 5 or more destroys the corvus). The base DC for either of these checks is 15, and the DC increases by 5 for every Small or Medium creature currently standing on the corvus. If a corvus is disengaged while creatures are standing on it, those creatures must make a DC 15 Reflex saving throw or fall. Succeeding at the saving throw allows them to move to the nearest area of safe ground, but such movement provokes attacks of opportunity. A corvus cannot be armored.