To determine whether hits are scored roll a D6 for each Attack a model has. The dice roll needed to score a hit on your enemies depends on the relative Weapon Skills (WS) of the attackers and their foes. Compare the WS of the attackers with the WS of the defenders.
Rolling to Hit
Source: 3rd-A-Palooza (3.5) Rulebook v1.4, p. 20