Turbo-Boosters This special rule is automatically lost by an independent character joining a unit that does not have this special rule, and vice versa.
Units mounted on bikes and jetbikes may utilise turbo-boosters to move at extreme speed. When using their turbo-boosers they may move up to 24" in the movement phase. Controlling their bike at such speeds takes all their concentration and skill, however, so they may not move through difficult terrain, shoot, launch assaults, or move in the Assault phase in the same turn. In the following enemy shooting phase, treat the bike's Armour Save as being an Invulnerable Save, to represent the difficulty of hitting such fast-moving targets. A unit using turbo-boosters must end its move at least 18" away from its starting position to claim this Invulnerable Save, as it relies on flat-out speed.
And They Shall Know No Fear Space Marines automatically pass Morale tests to regroup, and can take such tests even if the squad has been reduced to less than 50% by casualties, though all other criteria apply. If Space Marines are caught by a sweeping advance, they are not destroyed and will instead continue to fight normally. If this happens, then the unit is subject to the No Retreat! rule in this round of close combat and may therefore lose additional casualties if outnumbered. Usually troops that regroup may not move normally and always count as moving whether they do or not, but these restrictions do not apply to models with this special rule.
Units that include Servitors and Familiars are still subject to this rule as long as the unit contains at least one Space Marine.
Space Marines are still subject to Last Man Standing tests. They will always regroup after each Fall Back move to 'reassess' the situation however.