After briefly reviewing the information that has been obtained to date using 'H NMR to rationalise various phenomena associated with fluidity development, the improvements that can be achieved with various additives for poor coking coals will be described from both a practical and a filndamental standpoint. Trapping neutral oils from coal tar within briquettes prepared with phenolic binders enhances the mobility of the semi-fluid material for poor coking coal without significantly increasing the concentration. In terms of polymer additives, polyurethanes are unique in having a fluidity range that overlaps those of coals. Again, their addition vastly enhances the mobility of the semi-fluid material generated from poor coking coals but, unlike pitches, they do not dissolve any additional coal due to the high volatile losses. However, flexible foams have the ability to act as a plasticiser for much of the macromolecular structure in bituminous coals at relatively low temperatures (200-3OO0C). For high volatile coking coals, the addition of a petroleum coker feed (vacuum resid) can virtually render them completely fluid which accounts for the high yield of mesophase obtained in the resultant semi-cokes.