Strength should determine the damage dealt with hit and slam. Also, soldiers controlled by aliens holding a weapon with no ammo may generally attack in melee. Third, soldiers that are attacked in melee can pass a reaction test and turn and strike back against foes that attack them if they have sufficient time units. Aliens life forms, excluding terror units, generally don't attack in melee unless they react to a melee attack. However, with this function, aliens holding blaster launchers will attempt to bash soldiers who are up close with to kill them without blowing themselves up.