Welcome to Warhammer. Sound the trumpets and beat loud the drums of war, for the weighty tome you hold in your hands is your key to entering a dark and bloody land. It is a world of Daemons and sorcery, a brutal era of warfare and conquest. Warhammer, the game of fantasy battles, brings all the action onto your tabletop. You command armies of miniatures in a game that promises bold manoeuvre, daring riposte and untold slaughter.  The game of Warhammer makes you the general of an army of fantasy miniatures. Regiments of resplendent High Elves, the ragged hordes of ravenous ratmen known as Skaven, the Undead legions of the Vampire Counts or any of the other dozen army types, march, manoeuvre and charge into the fray on your orders. At your command, hails of arrows and eldritch bolts of magic are unleashed upon the foe. But it is in the brutal close quarters of combat that most battles must be won, by stalwart troops and legendary heroes.

Post 1.2 hotfixes, and added shooting in rear and front

Warhammer - The Game of Fantasy Battles - 9th Edition v.2.1

Main Rulebook

Blowpipe Profile

Blowpipe

All models in a unit should as much as possible be armed with the same weapon and armour type for ease of distinguishing their armament. Some variation is acceptable, but it should be clear to the opponent what sort of equipment a unit has. In case it might not be 
apparent at first glance, this should be clearly declared upon deploying the unit. If a model has more than one weapon, they must choose which weapon they want to use at the start of the shooting phase or close combat. A model cannot choose to use two different weapons in the same shooting phase or close combat unless clearly specified. However, if the model has multiple crew or riders (like chariots or ridden monsters), each crew or rider may use one weapon each as normal. Whichever weapon they select must then be used for the entire close combat, unless the weapon they are using is somehow destroyed – it's no easy thing to change to a different weapon partway through a fight.