Thanks for the analysis, KD; I think you bring up good points.
The problem is that it's all at the whim of the DM.
That's pretty true. One way that I hope to deal with this problem is by limiting the number of modifiers. You can get a total of +6 to attack based on what's happening. Defences can be higher, though.
Attack mods are:
Associated skill applies - +2 (I use a different skill system)
Situational combat advantage - +2
Following up on last successful action - +2
Defence mods are:
Target has situational advantage - +2
Target moves out of range in the round - +2 per 5’ out of range
Target has superior cover - +5
Target’s only action is to defend - +2
You are attempting a called shot w/o a power - +2
You cannot see the target - +5
I'm less sure about the Defence mods; still seems like too much.
For example, one DM states that the Ants charge while the PC is getting out the rope, hence, there is no +4 bonus to defense because the rope isn't there (or because the rope might be there, but the PC hasn't yet pulled it) before the Ants actually attack.
When the modifiers are applied, we don't know: if the ants are there before the PC is able to get out the rope, if they show up after but while the henchman is still within striking distance, or if they show up after the henchman scrambles up the slope of the hole.
What we do know is what a character can accomplish in a round.
A PC can pull out the rope and throw it and pull in the course of a regular round. That'd be a minor (get rope) and standard action (throw it and pull). That's what the PC does, and that's what will happen; we don't know yet if that happens before the ants reach the henchman.
The henchman can grab the rope and use it to help him climb out of the pit in a round. That'd be a minor (get rope) and move action (climb out of the pit). That's what he does, and that's what will happen; we don't know yet if that happens before the ants reach him.
The ants can charge the PC. That'd be a standard (charge) action. That's what they do, and that's what will happen; we don't know yet if the ants will reach him, nor if they'll be able to penetrate his armour with their mandibles.
(The ants could have climbed out of the hole, since they have a climb speed, but I didn't declare that as their action. Two reasons: first, is that they're stupid (a flimsy excuse!); the second is that I wanted to show the player of the henchman how moving out of range of an attack works when everyone goes at the same time.)
Now if we used 4E's standard initiative system, depending on who wins init, this could happen:
PC gets out rope, throws it to his henchman, and pulls him out
Henchman draws bow, shoots it at ants
Meanwhile, the ants are just standing around, watching.
That - the ants standing around, doing nothing, while the PCs take their actions - is really jarring to me.
In your example, not only does the PC get the rope out, but he manages to throw an end to the henchmen, he manages to hang on to the other end, the henchmen manages to get a good grip, and he manages to pull the henceman significantly fast enough to give him an extra +4 to defense (which is a huge bonus). Are the Ants 200 feet away??? The DM is also giving the henchmen a +2 to defense for the defensive action of climbing whereas a different DM would give the henchmen a -2 penalty for climbing.
Now for modifiers:
Since the henchman is going to end up out of the hole, which is 20' away from the ant's charge, he gets that +4 bonus. Hmm, I guess that should have been a meaty +8. Maybe I'll change that to +1 per 5'.
The henchman is just moving away. Since he's getting a rope thrown down to him he doesn't have to climb so much as scramble up the side (it was a sloped pit; he didn't take damage for falling in). I figured that was good enough for a purely defensive action, or +2. (Maybe I should tighten up the language.)
If the PC hadn't thrown that rope, then the climb would have been more difficult, and probably not a defensive action. Though still not enough to give the ants a +2 to attack.
Then we roll and see if the PC gets the rope to him and if he gets out of the hole or not. In fact, when we played, he didn't; the ants got to him and, while he ended up out of the hole (as was his action), he collapsed at the end of it.
It's not that it's more real and chaotic, it's that the DM decides a lot of rules that normal 4E already has baked in. On a good day, the DM gives the PCs all of these actions and bonuses in the small fraction of time that the Ants charge. On a bad day (or with a different DM), the PCs only get some of the actions done in a single round, cannot react in time to manage all of these actions or the modifiers might be totally different.
Yeah, I feel that it's necessary to have human judgement in order to allow fictional causes to have an effect on resolution.
Though all DMs should allow the PCs to get all those actions done in a single round, since clearly the rules state that they can.
Some of your rules sound strange as well. "pushing him back down into the hole gives you a +2 to AC". I have no idea the rationale behind this, especially if I miss with the attack. So as a player, I would be wondering why the heck the DM is handing out this bonus to AC for using Tide of Iron. The power doesn't give this bonus out. So regardless of whether I hit or miss, the monster gets a penalty to hit me because everything is happening at the same time and just the declaration of which attack I am using changes the outcome of the encounter, regardless of whether I hit or miss with that power. Or alternatively, if I hit I get the bonus to AC, but if I miss I don't, so we cannot necessarily adjudicate the results of the Ant's attack until we adjudicate my attack.
The +2 bonus is there because the ant's below you and you're putting your shield in his face and shoving him down. There's a situational advantage to the defender there - the ant's below him on slope of the hole.
Now if you did a wild overhand swing that situational advantage might dry up.
We don't need to know if you hit or not to know that you have an advantage.