For me, when all the mobs demonstrate the same tactical behavior throughout, it feels to me that it is the players vs. GM. While giving mobs behavior that they naturally would have is a more narrative approach.

Another good point for the morale/courage aspect. In fact, ignoring an attacker to go help out an ally may require a morale/courage/willpower test, to see if you even have the presence of mind to do it. The PCs may have to roll this for a grim and gritty setting.

Sometimes I just let chance takes over. I told the players recently, “I’ll roll a d6. On a 1 to 3, it will attack the fighter; on a 4 to 6, it will attack the rogue”. This is after both characters have badly hurt the mob in question.

If your players want a detailed tactical game, then by all means, meta-game and have cowardly goblins sacrifice themselves to charge the mages. If they want a ‘realistic’ simulation, then try and role-play each NPC’s motivations.

Also if there is a leader commanding the NPC’s, make sure to allow the PC’s to try and perceive who’s giving the orders, and to try and neutralize them. Include some contingencies for what the NPC’s do if the leader is slain.

Also, if the NPC’s are particularly brave and/or well-trained, make some perception-tests if/when spells start to get thrown around. A well-trained solider or a seasoned adventurer/villain should be able to recognize who’s casting healing spells, and -might- re-prioritize targets accordingly. On the other hand, not many intelligent creatures would risk several attacks of opportunity in order to take a shot at the mage.

This can up the challenge for the PCs, as they need to work in order to protect the squishies.

Well, there are other reasons. Though first I would acknowledge that everyone’s imagining of a game is different, so I am not mortified that the game is not story-breaking for others.

Second, the game is actually fine. In fact, if even great, just not my cup of tea for an actual pen and paper game. However, I also do get involved in computer games development, and there are a lot of things that D&D 4E can impart in that area.

You spent $100 bucks and some hours of your time so that you could say “I hate it, but look, I was fair”. And if that makes you happy, so be it. The system works just fine, and nothing in it keeps you from running it narrative-style. My 4e games tend to run half and half narrative and combat, just like they did in Vampire, 3e, 2e and well, pretty much all the other systems I’ve ever played.

I applaud your desire to appear fair, and your willingness to buy and read the rules. But you could have saved yourself the cash and time by just leaving it alone.

I can’t really describe the phenomenon, since I run 4e games with a lot of narrative, atmosphere and “fluff” if you will, and haven’t encountered any problems on my behalf or those of my players with the relationship between story and game (or lack thereof). In fact I’m a pretty story-primary DM and yet I run for, write extensively for and prefer D&D 4th Edition for my fantasy gaming.