Magus as Tank

I'm making a human magus for my group, and he'll have to be the tank. Any build suggestions?

(Yes, "Don't do it," very funny, ha ha. Moving on.....)

It's possible to build a magus to handle "many" enemies instead of "electrocute a few". Step away from optimizing Shocking Grasp and Snowball for a while and think about conserving your spells.

1) You'll need to use spells that improve your defenses. Spell Combat allows you to cast (defensive) spells while continuing to attack and hold enemies' attention. Spells of interest include Shield, Vanish (especially right after your attack, but before you 5ft step, to maximize enemy paranoia), Mirror Image and Displacement.

2) Maneuvers. Consider the old Dueling enchantment from PFS Field Guide. It adds twice your weapon's enhancement bonus as a luck bonus to combat maneuvers. Which means if you have a +1 dueling sword, you're level 5-8 and use Arcane Pool to add another +2 to your weapon, you get another +6 luck, and suddenly you're staring at a very high maneuver bonus. The magus class is really in the best position to leverage this enchantment because with Arcane Pool you can be ahead of the curve in weapon enchantment. The obvious maneuvers to look at of course will be Trip, Sunder and Disarm, since they can be performed with weapons and as AoOs. Remember using Vanish so enemies don't know for sure how to move without provoking you?

3) Spells that help you block off your fellow PCs.

• Longarm will increase your threatened area, stop people 5ft stepping or withdrawing out of reach.
  
• Bladed Dash moves you 30ft in a straight line, without provoking, and provides a free attack. With Spell Combat you can even follow that up with a full attack.
  
• Enlarge Person is difficult to cast (full round) but if you're using a Strength build actually attractive to you. See if any other PCs will use it to buff you. Alternatively, carry a potion. A potion of Enlarge Person can be drawn and drunk inside your turn, preventing enemies from interrupting. Once you're big you have more reach but you also simply block off more space.
  
• Sleet Storm makes it hard for enemies to come at you all at once, and protects against enemies trying to stay at range and target you. They'll have to wobble out of the storm, probably only a few per turn, making it easier to handle them.
  

4) It may be worth it to go for the Dex to damage build, with Dervish Dancer. Just get a commitment from the GM that if it gets nerfed in the future by Paizo that it'll continue to work like the way you took it right now.

5) Serious Constitution. You need HP.

6) Maintain your armor class. Good AC and Mirror Image work in tandem to make it really hard to hit you.

7) Hold enemies' attention. Be dangerous enough that they won't just provoke to move past you. (Trip maneuvers are also good for this.) Have a fair GM whose monsters don't learn from the previous encounter that didn't have any escapees, so every bunch of them has to learn over again that you're hard to hit. Make yourself look like an easy enough target (sleeves of many garments to hide your armor). Verbally taunt enemies (no game effect, but it works if the GM is into RP).

Starting from level 1?

What point buy, stat array or stat rolling method?

Do you just have to survive and do damage, or do you need to be 'sticky' to stop enemies walking around you?

Are all Paizo sources allowed, or some subset, and are 3rd party books allowed?

Just some basic stuff:

Shield spell is your friend

You will want to go high Dex/Int (there is an alternate racial trait to allow you to take +2 in both instead of the free feat...may be worth it)

I would concentrate on Rapier personally (Dex Fighter build basically) & maybe go Blackblade or one of the Ultimate Combat archtypes

Use your magic to control the battle field

Home game, Paizo sources only. Currently level 8, roughly a 20-point buy.

Other party members are Dex-based damage dealers (rogue, gunslinger) and casters (summoning cleric, bard, wizard).

My PFS magus - Mage Armor is the only active buff.

I would also at least consider Evangilist after 5.

there might be something to do with Whips and Enlarge for a 30' reach and Trip maneuvers to lock down enemies. Its not traditional tanking but can serve a similar purpose. Spell Combat True Strike and Trip for your attack and yeah, done.

Asc has some good advice above, but I think I can add a bit now.

Between the rogue and the summons you should be flanking fairly often. This would make the Dirty Fighting feat a cheap means of performing various combat maneuvers without provoking attacks of opportunity, when you're not invisible from Vanish.

The dueling enchantment can make your CMB very good but if you want to make absolutely certain get a wand of true strike, the wand wielder arcana and use spell combat with the wand.

While sleet storm would be nice to control the battlefield you don't get a lot of 3rd level spells. Euphoric cloud, web or stone call are 2nd level alternatives, and getting the fleeting spell metamagic can make these easier to work with. Color spray or glitterdust to temporarily disable enemies are worth considering too. With lingering spell, they could even fit into both categories.

Most archetypes won't be terribly helpful. Skirnir might be worth considering though since you're starting at 8th level when they finally get spell combat, and using a shield/buckler makes it easier to keep your AC up if you're going the strength route. Black Blade, Staff Magus or Hexcrafter are neutral in effect (though Staff Magus has potential later), Puppetmaster would limit your options a lot but would help you with illusions and enchantments.

When I've found myself as the only frontliner as a magus in PFS, I put a strong emphasis on defensive buffs. Shield, mirror image, and blur at lower levels, and moving on to things like displacement and stoneskin. Also, think about spellstriking with vampiric touch to give yourself temp HP and having spell storing armor with a nasty surprise built in for the first enemy that hits you.

I'm fond of spell storing armor with frigid touch. Immediately stops anyone trying to full-attack.

I'm fond of spell storing armor with frigid touch. Immediately stops anyone trying to full-attack.

Or FORCE PUNCH

I agree that spell selection is the big difference, and I love using the wand wielder and whatever the follow up one is called (allows you to use your CL in place of the wand's). From there I would have a high UMD (if possible depending on your other choices) and a large selection of wands to supplement your spell selection.

I also like using Kensai for this idea - losing a spell per spell level isn't a big deal if you have the wands to back it up, plus you get INT to AC and initiative.

If you can keep up the wand supply, Kensai with Wand-Wielder is a cute workaround to having fewer spells. Might want to commission an Unseen Servant to retrieve any wands you need to drop to cast other spells.

Then again, exotic weapon access isn't that necessary (but let's not underestimate the swordbreaker dagger), and the kensai pays for int-to-AC by not being so good at casting in armor. It'll depend on whether anyone in your party can cast Mage Armor on you whether it's worth it. Personally I prefer the regular magus with mithral breastplate.

If you're starting at level 8, a +1 dueling weapon should be within the budget as well as casting uninhibited in medium armor, so that's what I'd go for.

I'd go without any archetype at all really, because few of them have anything great to offer. Kensai loses out on armor (and armor enchantments), hexcrafter would be trading spell recall for (probably) the Flight hex. But as a tank the fly speed isn't as important as it would be for a behind-the-lines mage-killer sort of magus. And Bladebound can't get Dueling.

Let's not forget Arcane Strike and Bodyguard feats plus a +5 Benevolent armor as well as gloves of Arcane Striking. You can give a friend up to at least +12 AC by level 20 as an AoO. Which also works against spell that target AC.

Let's not forget Arcane Strike and Bodyguard feats plus a +5 Benevolent armor as well as gloves of Arcane Striking. You can give a friend up to at least +12 AC by level 20 as an AoO. Which also works against spell that target AC.

If you take the HALFLING HELPFUL trait (or the REGULAR HELPFUL trait if you're not a halfling & you don't want to be ADOPTED) and get a RING OF TACTICAL PRECISION you can get it up to +15AC (or +14 if you don't like halflings).

I'm sure there's more, but those 2 don't require much and get you to that nice round number.

For a long-term tank magus, you may want to consider myrmidarch.

Yes, you lose some spell slots and arcana. However, you gain Ranged Spellstrike at 4th (for some switch-hitting with thrown weapons; or one-handed firearms, if allowed) and both Weapon and Armor Training (to take advantage of the options in the Weapon Master's and Armor Master's Handbooks).