I've been playing around with CD3 some more and came up with a few house rules, so I though I'd share them here!
Pinning Fire: Attacks with ammunition types HE (high explosive) and SA (small arms) will only pin an enemy personnel stand instead of causing a hit if the die roll to hit comes up an unmodified "1" or "2." This rule does not apply in any of the following cases: if the target personnel stand is pinned (see Rule 7.46), if the target personnel stand is in covering terrain (see Rule 7.42), if an SA attack is against the flank of the target (i.e. the target is enfiladed by small arms fire), if the attack is a Close Assault (see Rule 7.7), if it is a direct hit from HE (see Rule 6.45) or if the result of "1" or "2" would not have normally caused a hit otherwise.
Rationale: I've remarked before that shooting is quite deadly in CD3. I find it a bit too "punchy" for my taste, with nothing in between a "no effect" result and a "permanent damage" result. Any damage is permanent damage, with no chance for an attack to inflict a temporary condition that can be fully recovered.
This house rule introduces a bit of cushion between the all-or-nothing shooting results that exist now and makes things a little more survivable. It also helps the attacker a little more than the defender (who will generally be in cover and thus won't benefit from the rule quite as often). The idea of the rule here is to distinguish between "area fire" and "concentrated fire"… targets in hard cover already have a -2 penalty to be hit (or better), so the near misses wouldn't worry them and those die values are covered by the penalty. Likewise, this gives a benefit to enfilading the enemy (which normally has no advantage in CD3), since enfilading fire will become proportionally more deadly than firing against the frontage of the target.
Enemy Contact: No unit may move within 5" of a known enemy unit except with a disengage or cautious movement order. Other movement orders will halt at 5" distance or at whatever point within 5" distance that the enemy is spotted. This rule does not apply to human wave assaults.
Rationale: This rule is meant to do a few things. Firstly it is meant to limit attackers suddenly bypassing a defender to infiltrate the defender's rear area. Units have very high movement rates in CD III and can race past defenders that flub their opportunity fire rolls. In reality, however, a leader wouldn't order such a reckless maneuver in close proximity to unidentified enemy troop formations. Cautious movement seems appropriate and avoids the gamey situation of racing into the rear area. The second function of this rule is to emphasize the use of reconnaissance. Currently, hidden units are a danger because they can surprise you with fire. With this rule, hidden enemy positions also become temporary roadblocks against your fast maneuvering troops, who must halt and assess the danger ahead for the remainder of the turn. Full advance and travel march should be only really be used away from enemy positions and the frontline.
