I could not find a post on ZAM about tanking and found this. This is a very old source though (March 2010) but thought I should share it with you all nevertheless.
Gladiator - Defense via Shield.
A versatile warrior class capable of taking the brunt from any foe while dishing out some damage of their own. Commands include Blocking, Slashing, and Thrusting.
Rousing Provoke (with sword): Increases enmity with a threatening gesture.
Cover: Take damage in place of the companion behind you.
Rampart: Reinforces physical and magical defense.
Still Precision: Reduce your evasion to increase your accuracy.
Aegis’s Boon: Converts some damage into HP when an attack is blocked by your shield.
Weapon Skills include:
Phalanx: With increased attack power, deal slashing damage to the enemy. Increases enmity. Can only be used following a block.
Red Lotus: A powerful attack with an addition effect of Fire.
Shield Bash: Deal blunt damage by bashing the enemy with your shield and interrupt their casting for several seconds.
Spinstroke: Slash attack that damages the enemy more if you are not its target.
Circle Slash: Powerful slash attack that hits all enemies around you.
Some opponents have too much accuracy to evade; some have too great of a reach to make polearms effective defense weapons; and some are just too powerful to take direct attacks from without a shield. This is where you shine, Gladiators--protectors when all others have failed.
Specialists with blades of all designs, you, too, can throw knives; incoming enemies can take one to the face. To add insult to injury, you threaten the enemy with Rousing Provoke. Enable Rampart to increase your defenses, and trade evasiveness for increased accuracy with Still Precision. You know your evasion is worthless, which is why you have a shield in the first place. And so, you use Aegis' Boon to convert some of that shielded damage into HP again.
Confident in your ability to block, you've saved enough TP to show you're not all about hiding behind your defenses. With every subsequent block, you successfully deal a Phalanx attack, adding more slashes to the face.
The enemy soon realizes that direct physical attacks are quite useless against your shield. So, it begins casting a powerful offensive spell. With quick wit, you Shield Bash the enemy, stunning it temporarily; this time, a shield to the face.
As a last resort, the opponent abandons honor and targets a vulnerable mage nearby. "(Stand behind me.) For I am your shield," you say. Cover allows you to take damage in place of your comrade. Still, the enemy focuses on the mage; a Spinstroke for extra damage gets the enemy's attention again. Spike your threat level with another Rousing Provoke as a reminder, "There is no enemy strong enough to overcome The Shield."
At the end of the day, you place your shield casually on your back, wondering if it will ward off would-be backstabbers.
Lancer - Defense via Weapon Reach.
Close to Mid-range combatant that uses weapon reach to their advantage by staying out of immediate attack range.
Comrade in Arms: Consume TP to place an effect on the enemy. When party members attack the designated enemy, TP generation is enhanced.
Ferocity: Increase the power of your next attack at the expense of HP.
Invigorate: Trade some HP for TP.
Collusion: Place enmity on one of your party members with your next attack from behind them.
Life Surge: With every successful attack, lowers an enemy’s evasion and absorbs its HP.
Weapon Skills include:
Overrun: When the enemy is not aware of your presence, close the gap between them quickly for a piercing attack with increased TP.
Feint: When used after evading an attack, with increased attack power, deal piercing damage.
Leg Sweep: Deal blunt damage to all enemies in front of you and prevents them from moving. Does not work on flying enemies.
Moonrise: A strong slash attack that temporarily inhibits the enemy’s TP generation.
Skewer: Hits all enemies between you and the designated enemy with a powerful piercing attack. Non-flying enemies will become slower.
Lancers are masters of teamwork. Like packs of wolves, they strategically work together to take down powerful prey. Less effective when faced with many foes, Lancers make up for it when facing fewer enemies of considerable strength.
Like wolves, lancers stalk their prey, waiting for the right moment to attack. When the enemy turns away, the pack leader sprints to Overrun the enemy. That's the cue for you to engage with your own Overrun from its blind spot. The real battle begins now that Comrade in Arms is designated; enhanced TP generation ensures your team can volley the enemy with repeated debilitating attacks. And to ensure every attack connects, all lancers keep Life Surge on rotation to lower the enemy's evasion and drain HP with every subsequent swing.
Easily topped with TP, it's your turn to Leg Sweep the enemy, keeping it in place where only polearms and arrows can safely reach. There is no escape from this lock-down. You can focus on offensive attacks, now that your turn is over. Attack with Moonrise to momentarily inhibit any TP generation. The enemy has its focus on you, but the distance is still safe. Follow through with a Feint maneuver for extra damage when the enemy misses.
At this point, you realize your enmity out-paces your partners' too much, and you've used up your TP reserves. Quickly Invigorate to boost TP just enough for one more Weapon Skill. Preparing to use Collusion, you place yourself behind a partner. Here it goes... Collusion... Ferocity... and then Skewer! Hopefully you aimed well enough not to stab through your partner. Alas, the enemy's focus is on the leader; enmity is balanced again.
Keeping the enemy at bay while bouncing its attention between the various lancers has minimized any major damage, and thus, minimized expenditures. Once the enemy has fallen, continue to the next one uninhibited.
Marauder - Defense via HP Restoration
Close-range combatant that specializes in variable-range AoE attacks via the Steadfast stance.
Bloodbath: Damage done on your next attack restores your HP.
Murderous Intent: Increases critical hit rate but reduces TP generation.
Defender: Raises physical defense at the cost of attack. Increases enmity while in 'Steadfast' stance.
Disorient: Lowers the enemy's evasion; effect stacks up to three times.
Enduring March: Continue moving, although slowly, even if bound in place by magic. Maintains 'Steadfast' stance even while moving.
Weapon skills include:
Skull Sunder: A powerful slash attack that targets a single enemy's head with with additional DoT effect. Can hit multiple enemies in front while in 'Steadfast' stance.
Trunksplitter: A powerful slicing attack that is effective against Seedkin (plant-type enemies).
Fracture: When used after deflecting an enemy’s attack, does bludgeoning damage and disable’s the enemy’s weapon skills.
Brandish: A powerful slash attack to all enemies in the surrounding area.
Iron Tempest: A donut-shaped wind-elemental attack with you at the center.
Ever step foot into the Limsa Lominsa Adventurer's Pub to find an all-out brawl ensuing? And then look around to notice the single cool guy standing still in the middle of it, with his arms crossed, eyes closed, and a stone face? If not, you'd be smart to take a step back soon. The cool guy is secretly a Marauder--not much of a secret with that giant Axe, though. He's in his Steadfast stance, charging up for a massive-damage surprise attack on all the others fighting obliviously to his presence.
What's important to realize is the Marauder class truly excels in situations where a large enemy encounter is present; at the same token, this class has minimal effects in single-opponent combat. With skills to increase attack range and damage, a Marauder can easily replenish his or her HP by combining moves with the Bloodbath ability. Furthermore, to increase effectiveness, abilities to increase critical hit rates, and lower enemies' evasion are possible.
Coincidentally, you're a Marauder, too. And in the heat of it all, you can't help but dabble in a little bit of the brawl. You jump in unleashing an Iron Tempest from the start to get everyone's attention. Once that's done, wisely use Defender to mitigate damage, and at the same time, increase enmity generation while in Steadfast stance. All the fighters, including Mr. Cool Guy, have their attention on you now. You begin to take damage as the fighters slowly chip away at your HP. Mr. Cool Guy stands back to observe you still.
Your cockiness begins to reveal itself. To show Mr. Cool Guy what you're made of, you prepare your most powerful attack combination. With Steadfast at maximum yield, and your opponents gathered... SUPER-DUPER COMBO #5, GooOOooo!
Murderous Intent! Bloodbath! Skull Sunder! All in quick succession.
Although exhausted, the 'Super-Duper Combo #5' has defeated all your enemies. Luckily your HP is full thanks to Bloodbath. Catching your breath, you feel Disorient and look up to find Mr. Cool Guy lunging at you with the same attack combo! There's no way you can dodge this attack due to lowered evasion. Your face slams the floor with tremendous force; the fracture in your skull signals you've been defeated. All the while, recalling he had been in Steadfast stance the entire time.
Mr. Cool Guy departs with a good lesson told, "Time your attack better." It's the first and last time you'll ever see him. Those words, you'll never forget.
Pugilist - Defense via Evasion
An agile hand-to-hand specialist that's effective against enemies with mid-range to long-range reach advantages by quickly closing the distance. Can throw Chakrams which can temporarily daze an enemy. Defensive and Offensive stances are possible; the longer you maintain the stance, the stronger they get.
Mocking Provoke: Whistle to gain the enemy’s attention and increase enmity.
Blindside: Critically damage an enemy from behind; attack power is increased by +50% Dexterity.
Chakra: Heals HP by using TP.
Steal: Take a random item from the enemy; success increased with 'Stealth'.
Featherfoot: Significantly raises evasiveness, but only once; at which point, effect will fade slowly.
Weapon skills include:
Jarring Strike: Stuns the enemy with bludgeoning damage if used right after evading an attack. Will increase enmity level.
Victimize: A slash-based attack. Critical rate raises for every enfeebling effect on the enemy.
Haymaker: A powerful bludgeoning attack if used immediately after dodging.
Shoulder Tackle: Quickly close the distance between you and an enemy and attack with blunt force.
Seismic Shock: Long-distance earth-based attack that hits all enemies in range. Does not work on flying enemies.
A Pugilist doesn't need heavy armor; on the contrary, it slows them down. Instead, they rely on their lightning fast reflexes to evade attacks and counter with lethality of their own. This class is meant for those daring enough to test every ounce of skill.
As a Pugilist, you can get an early advantage by maximizing your Defensive stance before battle. Once the battle starts, use Seismic Shock on incoming enemies. Follow through with a Mocking Provoke to spike your threat level. With good anticipation, you can sense when a powerful attack is coming. To answer, you enable Featherfoot to dodge the attack, and follow through with Jarring Strike to temporarily disable the enemy, all the while increasing enmity. You know your evasion is still high, and so you save enough TP to Haymaker the enemy when they miss again.
Some opponents are smart, and realize it's a futile battle; so, they flee or target someone else. A Chakram throw to the back quickly stuns the enemy. At this point, your target is well into battle, and should have plenty of enfeeble effects. Abandoning your Defensive stance for an Offensive one, you quickly close the distance with Shoulder Tackle, and enable Blindside to Victimize the enemy for maximum damage.
An easy fight, but you're left with a few scratches nonetheless. It's nothing a Chakra ability can't fix.