A bailey describes various evolutions of a wooden or stone fortification intended to enclose a hamlet or yard that might include a bakery, kitchen, chapel, storehouses, stables, barracks, forges and workshops. In it original form, the "bailey" describes a simple palisade wall that may or may not include a protective ditch. With time, as a settlement grows, the original wooden construction is replaced with stone. Many early baileys include an adjoined defensive mound called a "motte," that's later fashioned into a citadel. Eventually, the bailey and motte are transformed into a full castle — though castles that are built whole still use the terminology of "bailey" to describe one or more yards connected to the main fortification.
The moat, if possible, was formed by diverting a stream or part of a river with dams or ditches, the water being held by a second dam to maintain a proper level before being released back to its natural course. The point where the dam releases the moat serves as a good place for a gristmill or other like construction.
The bailey hamlet calls for the construction of a stakewall, or palisade, surrounding a community's chief buildings. This type of fortification can be found around hamlets with 2 hammers in type-6 or type-5 hexes. Made of sharpened tree trunks planted in the ground and bound together, bailey palisades vary between 10 and 13 ft. The bailey can be readily rebuilt when called for with materials on hand; in short-term conflicts, they are effective against raiders and large vermin.
Type-6 baileys don't employ a moat, but a ditch with thorny brush and buried stakes make a useful alternative.
With a type-5 infrastructure, the motte is added to the same approximate bailey that also appears in type-6 hexes. Simple mottes are flattened hill some 30 ft. high and 120 ft. in diameter. This construction is supported by a moat where sufficient water is available or a fortified ditch otherwise. It's common for a hamlet to be located where a motte occurs naturally; otherwise it must be physically built with wooden shovels, picks and hand-barrows, requiring an estimated 1,000 man-hours of work.
This is a placeholder for further adjustment and elaboration.