Greater fantastic machine was an illusion spell exclusive to clerics with the Craft domain. It called into being a large illusory mechanical contraption that was controlled by the caster to perform simple tasks.
The machine was imposingly large and noisy, with wheels and many arms with tool appendages, and was constructed of adamantine to be extremely tough and strong. The machine could roll on its wheels, swim, or fly. The movement speed was as fast as an unencumbered human on land but one third the rate when swimming or flying. The maximum load it could carry was 1,560 lb (709 kg) on land and one third that amount when swimming or flying. Standing still, it could lift double its maximum load to a height of 15 ft (4.6 m). It could push or drag a 7,800 lb (3,550 kg) load over land. It could also excavate a 5 ft (1.5 m) cube of rock and dirt (about 20,000 lb or 9,100 kg worth) in one minute.
The machine was similar to an animated object and could perform simple tasks autonomously or have each movement controlled by the caster. If ordered to attack, it was effective in slamming its target, having the greatest success against stone or metal targets. It could hurl small boulders with good accuracy. If a target had any resistance to magic, then it was possible to resist attacks from the machine. The duration of greater fantastic machine was one minute per level of the caster.