Gish is a /tg/ term relating to character classes, and specifically refers to a character who is capable of both melee combat and magic with relatively equal adeptness.
Gish originated from Dungeons & Dragons, where the githyanki had an elite caste known as the gish; githyanki using the multiclassing option to become fighter/wizards of considerable lethality. The archetype stuck fast in the D&D munchkin consciousness and it has remained a fixture of /tg/ ever since. The concept is referred to in homage to the githyanki, who started it all... at least, if you were playing Advanced Dungeons & Dragons; the actual idea of the gish has been around since Elf was a class in Dungeons & Dragons.
Traditionally, most gishes are the result of multiclassing, or dual-classing, or hybrid classing, depending on edition. However, certain classes have increasingly been designed to support this from the ground up, due to certain inefficiencies in the multiclassing approach - most notably, the XP Tax. However, most "made" gish-classes have traditionally been "warriors, with a little magic"; examine the Paladin (fighter with some low-level Cleric spells and tricks) or the Ranger (a fighter/low-level druid blending). More melee capable mage types have been a rarity; the Swordmage of 4th edition D&D, Pathfinder's Magus, or the Bladesinger Wizard and Stone Sorcerer of 5e, for example.
The earliest "level 1 gish class" appeared in Basic D&D, in the form of the Elf racial class. required a minimum Intelligence of 9 to qualify for the character, and needed high Strength and Intelligence to gain bonuses to XP gathering. They had a D6 hit dice, started play with the Set Spear vs Attack and Lance Attack fighter manuevers, were immune to the paralysis attack of ghouls, and had a 1 in 3 chance to detect secret or hidden doors. Technically maxing out at 10th level, they gained a fairly small selection of mostly low-level spells, maxing out at 3 spells for each level from 1st to 4th and 2 level 5 spells upon hitting 10th level, but could keep gaining experience after 10th level to increase their attack rank, maxing out at Attack Rank M. At Attack Rank D, they gained the Fighter Combat Options and could make 2 attacks per round. At Attack Rank G, they halved all damage taken from breath weapons (quartering it if they passed their saving throw). At Attack Rank K, they could make 3 attacks per round.
Dawn of the Emperors: Thyatis and Alphatia introduced the Forester class, a human trained by elves who thusly has learned to blend martial skills and magic the same way that they do. To represent a forester, you took the Elf class and stripped out the Infravision and Immunity to Ghoul Paralysis traits. That's it; do that, and you're good to go.
Gishes frequently show up in fantasy-based video-games, usually as a more "elite" version of normal classes. One of the /v/ gishes most well known on /tg/ is the Red Mage of Final Fantasy, a character class that combines Black Magic, White Magic and melee fighting skills into one singular class; it can't become as good in any one of these fields as a specialist, but its broad, well-rounded skill-set makes it one of the most versatile (and powerful) classes. A party composed entirely of Red Mages is considered basically the beginner's group in a game of FF1.
List of Gish Classes
Without directly multiclassing, these classes directly amalgamate martial and magical prowess into one class.
- BECMI Elf
- BECMI Forester
- BECMI Gruugrakh Gnoll
- Paladin (divine gish)
- Bladesinger (a fighter/mage multitclassing kits for elves in AD&D and a prestige class in 3e, but its own thing in 4e and 5e)
- Hunter (Pathfinder)
- 5e Warlock (via Pact of the Blade sub-feature or Hexblade subclass)
|The Gith of Dungeons & Dragons|
|Races:||Duthka'gith - Gith - Githyanki - Githzerai|
|Undead:||Kr'y'izoth - Tl'a'ikith|
|Individuals:||Vlaakith CLVII - Zaerith Menyar-Ag-Gith - Zerthimon|
|Places:||Shra'kt'lor - Tu'narath|
|Miscellaneous:||Crown of Corruption - Gish - Scepter of Ephelomon|
|Adventures:||Incursion - Scales of War|