While participating in combat (be in against mobs and NPCs or versus other
player characters), you may wish to come to the assistance of an ally. You
may do this using ASSIST <ally>.
The ASSIST command is somewhat akin to having an extra target (see HELP
TARGET). While assisting, all of your commands will prioritise targeting the
same target as whoever you're assisting has set, so long as you're in the
same location as your ally.
UNASSIST can be used to discontinue assisting your ally.