By the way, D-Team Thread For You -- about parties with no full casters and maybe not even 6/9 casters. And by the way, Thread Necromancy Welcome.
When people say "tank" in Pathfinder, it irks me. I'm an old Everquest player. I know what a MMO tank is. Fighter has NEVER been that tank. Pathfinder's Fighter is a melee DPS.
...Anyways, back to 'Tanks'. What makes a tank is an ability to force things to attack you. 4th edition D&D has that. Pathfinder has a spell that does that. Fighters don't get it at all. Fighters are not Tanks. If you are making a 'tank' for your group, you are doing it wrong. Make a DPS that scares the other side enough they won't ignore you!
I would argue that drawing aggro is a way to tank, but is not the only way to tank. A tank reduces the incoming damage for the squishies, whether that is by drawing aggro, debuffing the enemy offence, or providing barriers/temp hp. Aggro tanking is generally the simplest because it works well with combat healers: a lot of tanking is ablative, and hit point healing restores what an aggro tank needs to keep tanking.
I have a mesmerist I enjoy a lot in the tanking role, as both a debuff and aggro tank. Pure aggro tanking is often difficult in PF because how healing works is not balanced for dedicated tanks. But forcing an opponent in a specific direction while they're at -7 to hit is still a noticeable defensive aid.
I do side more with Meirril on this issue. Calling a fighter a tank makes the player think that the fighter can easily defend the party. In Pathfinder, defending the party takes a lot of work.
The nature of the fighter that tempts people to call him a tank is that he has endurance under combat. A rogue or magus can deal a lot of damage, but often he has to retreat before combat is over. He does not have the AC and hp for sustained combat. Fighters, rangers, and paladins do. Some barbarians do, too. Sustained combat is a valid role in the party.
Instead, I call the Fighter class a frontliner. That is one of the few times that a fighter can defend the party, when he is on a protective front line that the enemy cannot get around. The classic scene is the 10-foot-wide hallway, with the fighter and cleric shoulder to shoulder blocking access to a wizard and archer behind them. Out in the open the enemy could walk around the front line, but doing so would delay the enemy one round. That, at least, protects the vulnerable party members for one round.
Debuffing and battlefield control are other ways to defend the party, but those tactics have their own names and usually are not included in the term "tanking".
It all comes down to how you define a “balanced party”. When the game had fewer classes and archetypes did not exist the only way to get certain abilities was to have the proper class. That is no longer the case. Now it is extremely rare to find something that only one class can do. Even in cases where a specific ability is only available to a single class you can often find ways to accomplish the same or similar thing with another class. I honestly cannot think of a single thing that only one class can do that no other class can accomplish. I am not talking about specific game mechanic or access to specific spells, but rather dealing with the situation that the game mechanic or spell was designed to accomplish. I challenge anyone to find something like this.
Now if by balanced party you mean having a wide variety of options available to you that is a completely different story. For a party to be successful they are going to need to be able to deal with any obstacle that the GM throws at them. Keep in mind dealing with the obstacle does not mean you have to be specialized in handling it. While the melee focused fighter may not be as good at archery as the dedicated archer he can still pick up a bow and use it. He is not going to come anywhere near the damage of the dedicated archer but he can at least do something. So can most of the rest of the party. Sure a dedicated archer can take down the target in a round or two, but a group of lesser ranged combatants can eventually do the same thing.
In all honesty I think it would require a conscious effort by the players to create a party that all do exactly the same thing. Unless the players get together and all decided to run identical characters there is going to be some diversity in the characters. Even if the party is all a single class there will usually be enough variation to give enough diversity.
The real question comes in figuring out what a balanced party is. This is going to depend on the nature of the campaign and the group. If the GM does not including any traps the role of trap finder is unnecessary, but if he does included traps the party is going to have to deal with it. A good GM can adjust his campaign to deal with anything. But on the other hand making the GM’s job harder like that is the mark of a poor player. This is especially true if the GM is running a published AP.
Anyways, back to 'Tanks'. What makes a tank is an ability to force things to attack you.
No. A "tank" is someone who can survive large amounts of incoming fire/attacks/spells/etc. You know, like the armored vehicle it gets the name from? That's literally the only general definition of tank: A character with very high defense. To be a tank, you don't need any aggro mechanic, damage dealing capabilites, or anything else apart from being able to survive playing punching bag. You might need some extra stuff to be a useful tank, but not to be a tank at all.
The term tank is used in games without an aggro system. The term is even used for solo play (or rather, used to be).It isn't even a "you soak damage" kind of melee, its actually a damage avoidance type.
I don't get it... why is that relevant? Damage reduction, avoidance, healing back up, even being outright immune - all means to the same end. I've seen and played all sorts of tanks. I've played tanks with 1/10th the HP of the rest of the party. I've played tanks that purposfully lowered their AC (which provided damage reduction in that game) because they wanted to get hit by a lot of damage by every attack (~3 times what the rest of the party would take). I've played tanks that almost exclusively relied on high HP. I've played tanks immune to all attacks and targeted spells.
Wait, what? You can assume that no one in a PFS party has high perception? For real?This was my experience in PFS games. Searching for traps often lead to finding nothing and getting hit with the traps we failed to find. I admit I've done only a handful of PFS games because I didn't enjoy them and so my experience may be atypical.
Did the characters not max perception (plus maybe Seeker trait or something), or were the DCs simply to high?
I think every party needs someone who can use a CLW wand for out of combat healing. Past that, a balanced party helps but isn't necessary.
Or someone who can use wands of Infernal Healing. Which means 20 classes (out of 40 if you include alternate classes), not counting archetypes or Medium, can use a wand to heal.
A couple of sessions ago, a ghoul or something got hold of our dwarf and drained half of his HP. Too bad for the ghoul, that's still higher than everyone else's full.
I call this "growing a party organically." It leads to a party optimized to work together, but not necessary optimized as stand-alone characters. Since Pathfinder rewards teamwork, an organically grown party is stronger than a theoretically optimized party.
This is what I was getting at in this line: "If the players find themselves without heals, lock picks, or relevant spells, then that’s an interesting challenge." Being stuck on the wrong side of an impassable barrier sucks. Getting to go back to town, lay down some coin, and come back with a jackhammer is the interesting part.