The main reason is the versatility of your main feature and the required bookkeeping and the increased amounts of actions in a turn . You see , as a summoner , you summon stuff . First , you need to know what you want to summon if it isn ' t your eidolon . You have to make a decision out of a fairly big list of things you can summon . Then you have to keep an eye on not only your stats , but also their stats . You have to know their HP , saves , special abilities , how many turns they remain and so on . Then , when it is your turn , you have to coordinate all your summoned creatures , which can become a lot if you also take the summon monster spells . You have to essentially make numerous turns at once with different stats all in one go , which can really slow down games if you aren ' t familiar with what to roll when and common tactics . It ' s not really that the summoner is hard to play . He actually is very hard to build wrong and is fairly straigth forward most of the time . The issue is rather that you almost always at least have two characters to play and are expected to still resolve everything roughly in the same time others do their actions to not bore everybody at your table to death . It is rather ambitious , though I don ' t want to keep you from doing it if you like this class best .