Key thing to note about Spellsword prerequisites:
- A candidate for Spellsword must have proficiency with all simple & martial weapons, as well as proficiency with all forms of armor (light, medium, & heavy). They must also be able to cast 2nd level arcane spells.
- Bards & hexblades can cast their spells while wearing light armor with no penalty, so the lower levels of Spellsword won't really be that useful for them. Besides, mithral medium armors count as light armor, so bards wouldn't have to worry about that. Hexblades start off with light armor proficiency only, so they'd have to burn 2 feats in order to qualify for this PrC.
- This prestige class works best for fighter-mage combos who don't really have very high Dex scores (maybe a 16 Dex at best). With 9-10 levels in Spellsword, a spellsword wearing mithral full plate has no ASF chance; the mithral would decrease the ASF from 35% to 25%, and the max Dex bonus allowed jumps up from +1 to +3. It's the best combination for the class abilities---otherwise, the required Heavy Armor proficiency goes unused.
- The only non-mage classes that can qualify a character for this PrC is fighter or paladin (or the samurai from Complete Warrior). Clerics lack the prerequisite proficiency with all martial weapons; barbarians lack proficiency with heavy armor; rangers lack proficiency with medium & heavy armor.
So, the immediately viable class combos to qualify for a Spellsword are:
- fighter/wizards
- fighter/sorcerers
- paladin/wizards
- paladin/sorcerers
Above all, the fighter/wizards & fighter/sorcerers work out fine either way (one casts a greater variety of spells, while the other casts a greater volume of spells). The paladin/sorcerer is more preferable than the paladin/wizard, since the Charisma requirement for his/her sorcerer spells would add in to his/her Cha-based paladin abilities (like the saving throw bonuses & lay on hands ability).
But, the price for a spellsword is that he/she will not be able to cast 9th level spells (and possibly 7th- & 8th-level spells)
without going epic. You can channel a spell through a weapon strike a couple of times a day, you'll be better off than a straight fighter-mage multiclass (higher effective spellcaster level, plus no need to memorize/cast a lot of spells with the Still Spell feat & eat up higher-level slots for lower-level spells),
but you'll still not be as powerful as a pure mage. An eldritch knight will be able to cast higher-level spells than a Spellsword
without going epic, but the eldritch knight candidate has to cast 3rd-level arcane spells (& not just 2nd-level) will still need to prep with Still Spell in order to cast spells in armor.
An elven or half-elven bladesinger is a racially-specific alternative to the Spellsword--it's best suited for lightly-armored agile characters. The best class combo for a bladesinger is, IMHO, a swashbuckler/wizard (using the Swashbuckler core class from
Complete Warrior). The Intelligence requirements for wizard spells stacks
exquisitely with the Int-based precise strike ability of the swashbuckler, and the Int-based AC bonus of the bladesinger. And, this class combo really complements a high Dex character, because 6th level bladesingers have ASF in light armor, and the Weapon Focus (rapier) works wonderfully with the free Weapon Finesse feat gained by swashbucklers at 1st level. With a swashbuckler/wizard/bladedancer, you need only worry about having a high Int & Dex--with a bard/bladesinger, you'd need a high Dex, Int, & Cha.
I will say one thing, though--IMHO, I think that a bard is a
much better option for an arcane archer than any sort of fighter-mage combo. It may take a bard a level more than a fighter-mage combo,
but the bard can cast his/her spells in light armor, as well as have higher level spells available than a straight fighter-mage candidate.
Now all there needs to be is a sort of mystic theurge-kinda class that also grants ASF reduction or the like, & there'll be some pretty tough cleric/sorcerer combos out there.
