Summoners are priests of nature (with some nature/survival support spells) who can summon friendly monsters to help them against hostile monsters. They have the worst stats of all classes: they fight as badly as Sorcerors (1bpr max, huge penalties to melee and shooting) and share their low hps (base dice 0, -5 starting CON). In fact, they are probably the class counterpart to the Yeek race and should be played as a challenge class. For an almost impossible challenge, try a Yeek Summoner (-10 starting STR/INT/DEX/CON).
What is the best race for Summoner? I've tried many, and clearly couldn't get any race going except Dunadan. Thunderlords also make decent summoners, but you will have to deal with the insane xp penalty. Dragons will have the same drawback, but the innate breath weapon can make the early levels much easier. Ent could also be a decent choice, but you will start with -9 DEX (and lower CHR, which is one important stat for summoners). Another choice would be Hobbit which starts with decent stat boosts and a bonus to shooting, but you will start with -7 STR and get really low hps the whole game. Avoid Dwarf, which has a starting WIS boost, but won't be able to survive the early levels due to pathetic skills at shooting. And avoid any race that doesn't start with decent WIS/CHR, or you won't be able to summon useful monsters.
Summoners rely on their summons. Once they get decent WIS/CHR, they will have a better chance of summoning friendly monsters, and more important, monsters that will be able to attack other monsters.
So how to play a Summoner? At low level, you will struggle a lot to stay alive. Your best bet is getting an enchanted weapon with the biggest possible dice (Farmer Maggot, quests...), an enchanted shooter and a "magic" ammo (shot, bolt, arrow). Shoot everything you can with your launcher (this is why choosing a race with shooting bonus is important). Try to get extra WIS/INT before summoning (low level summons are usually crap anyway -- jellies, worms -- and tend to be generated hostile/static). Look for Rings of Polymorphing if you can. At high level, summon and watch your summons kill monsters and soften uniques for you. I'm still looking at trying Morgy with a summoner. It should be fun...
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