In the rule “Orbital Dockyards”, replace “If a Shuttle’s Orbit contains an Orbital Dockyard, that Shuttle may spend 1 tonne of any Saleable Substance to replace one of their own XDICEY Thrusters with an ADICEB Thruster, where “A” and “B” are positive integers whose sum is equal to “X” plus “Y”.” with:-

If a Shuttle’s Orbit contains an Orbital Dockyard, that Shuttle may spend 1 tonne of any Saleable Substance to either:

• Replace one of their own XDICEY Thrusters with an ADICEB Thruster, where “A” and “B” are positive integers whose sum is equal to “X” plus “Y”.
• Replace one of their own XDICEY Thrusters with an XDICEB Thruster, where “B” is one greater than “Y”.
• Gain a DICE4 Thruster.