X-Com: Gray Dawn Shotguns
Contrary to popular belief (and the FNFF rules), shotguns are not exactly area-effect weapons. They still need to be aimed, especially at standard combat ranges. The CP 2020 rules regarding shotguns are somewhat confusing; they seem to imply that no hit roll is required, and they vastly overestimate the spread pattern. Since we are using an opposed-roll system, shotguns will have an improved attack bonus to reflect the fact that they do spread. At close/medium/long range their bonus is +2/4/6. Their damage is reduced at range as described in the FNFF rules.
Because of their spreading bonus, shotguns are good for overcoming the bonuses granted by several factors, such as cover. If a body part protected by cover is hit by a shotgun, the cover only provides 3 SP/level instead of 4; the spreading nature of the attack means that some pellets may be striking areas that are not covered.
Shotguns raise the target number for suppression by +1/shot rather than the regular +1/attack because of the area they cover, the damage they cause and the psychological impacts of these effects. If you can pour multiple shotgun blasts on a target, it tends to make them duck.