To follow up on my post from last week, I thought it would make sense to analyze some possible house rules to improve the D&D minion rules. By house rules, I mean trying to adjust the rule to fix problems while remaining as true as possible to the original rule and the spirit of the fourth edition D&D game, rather than trying to rewrite the rule from the ground up.
A. The simplest and most obvious rule is to make minions immune to automatic damage just like they are immune to miss damage. This would probably be best stated as "minions are only vulnerable to damage from attacks that hit"; that would make sure they can still be killed by cleave, which is one of the few powers that really, really should work well against minions.
Though simple, this rule would not work well. Minions would be totally immune to all sorts of things which they clearly should not be immune to. They could dance through walls of fire and so on. The other rules which follow are more practical.
B. Minions could actually have hit points like real monsters, but any damage coming from an actual hit still kills them automatically. Maybe they have ¼ as many points as a real monster, but this is only used against automatic damage. This rule is fair and solves the problem, and retains most of the simplicity of the original minion rules. The main disadvantage is that it also loses one of the big benefits of the minion rules, that you never have to keep track of hit points for minions. It also has the strange effect that softening up minions with automatic damage not only wouldn't kill them, it wouldn't even make them easier to kill with normal attacks. That is, whether a minion is healthy or damaged, it still takes only one real hit to kill it. Whereas against a normal foe, causing a small amount of damage early on makes it takes fewer attacks to kill later.
C. Minions could ignore automatic damage below a certain amount, as if they had “resist damage”. This would not require any bookkeeping, and would give minions a certain amount of dignity. The disadvantage is if the amount of damage ignored is low, such as level/2, a lot of things will still automatically kill the minion. While at the amount of damage ignored is high, such as level +2, they may become immune to some effects which are pretty powerful and which they should not be immune to. In either case, it doesn't do a very good job of solving the problem that many attacks will either always kill the minion or never kill the minion. But it does make the minions seem less pathetically puny.
In this case and the previous one, it would make sense that attacks which miss should be considered identical to automatic hits - they can still kill if they cause enough damage.
D. Minions can only be killed by a successful hit, and damage that does not normally require a hit roll is allowed to make a hit roll for the purpose of killing the minion. This is probably the best solution in terms of solving the underlying problem that automatic killing is boring. One disadvantage is that it requires extra dice rolling. The bigger disadvantage is that it strays much farther from the normal rules than the other options. In particular, automatic damage is often somewhat disconnected from the character who creates it, so would not always be clear what hit roll is being made and what the bonuses are. It would essentially open a "can of worms" where the DM would have to make quite a few house rules to support it.
All of these solutions have definite problems, none of them is an obvious replacement for the current rule and there is definitely room for argument over whether any of them are actually better than the current rule. However, if you wanted to make a house rule, B, C, and D all sound quite plausible.