krakistophales
First Post
Gish is a fighter magic user, and while it's exact definition varies from edition to edition, in this edition it generally means cast arcane spells and gets at least two attacks per attack action. It's from the AD&D days when people would play Githyanki fighter/mages, gith got turned into gish.
As for whether or not eldritch knight sucks, well that depends. It's a perfectly functional class, but their abilities are somewhat at odds to how they are usually built. For instance they can grant disadvantage on saves, but don't have much in the way of save or suck, nor would they given they are usually built with a low spell casting stat. With that said they are built on the rock solid base that is the fighter, so it's pretty hard to screw it up. Are their better choices if you want to build a Gish, certainly, but it's a pretty low effort build.
As soon as we add multi classing things get different, There are two logical breaks for multi classing lvl 7 (two attacks and war magic) and 11 (three attacks and Eldritch strike).
7th is the best break point level because of war magic. Green flame blade includes a weapon attack and when you add another attack from war magic you are getting into some seriously respectable at will damage. That also gets you an extra ASI which will offset the one you loose from multiclassing at a non divisible by 4 level. You also get action surge (one of the best nova abilities in the game), a fighting style, and fighter proficiency. You then add wizard to this, and your EK levels give you two additional levels of spell slots. You'll finish at 20 with a seventh level spells, and an eight level slot. At this point blade signer doesn't get you much since you'll be rocking heavy armor and a dex dump stat, so I'd suggest picking abjuration as your wizard college because you'll be in melee and be using quite a few abjuration spells, which means a lot of temporary HP.
11th is the other break point, but the three attacks is kind of wasted, since you'll get similar results from green flame blade. The real gem is eldritch strike, but you won't have many wizard levels to get those save or suck spells to take advantage of the disadvantage.
How does EK 7/wizard 13 stack up to the other gishes, fairly well. Unlike the blade singer you have a reason to be in melee, and unlike EK your spell casting is actually decent.
So is it the case then that taking 20 levels of EK will always be an inferior choice, both in terms of DPR output, utility, and versatility to either a multiclassed EK/wizard or better straightforward options like paladin/tempest/war domain cleric? Sorry if I don't mention valor bard or bladelocks here, but bladelocks don't get martial prof/heavy armor like paladins and domain clerics do, and I know nothing about valor bards.