I thought there were alittlebit too few discussions on the forums about the characters you are playing in the Baldur's Gate series (EE). Therefore, I'd like to present mine - perhaps it might help future generations when deciding which character they will play. I'd also like to point out that I am roleplaying through and through and are not powergaming whatsoever. I also have all the addons added by SCS, insane difficulty etc. I've changed his avatar to that of an half-elven/elven mage, instead of that of a half-elven/elven cleric, with Shadowkeeper.
Let me present Gaius, or Gaius the Wise as some of you might know him. Or as he calls himself, Gaius the Scholar of Candlekeep. Gaius was inspired by his foster father's knowledge of the magical arts and made especially productive use of his library home. He have learnt as much as he can as he pored over the vast treasury of magical lore and holy books. The strength and power of faith inspired him and from this he came to worship the God of Azuth, the Lord of Spells. Gorion instructed him in the basics of the Art, while the Avowed graciously fielded his many questions and taught him much about the clergy. Gaius know, however, that experience could teach him so much more, and he yearn to travel the Sword Coast in search for knowledge and wisdom.
A cleric/mage is a spellcaster through and through. As such, this character is in dire need of martial protection. Since I'm roleplaying I'm not using shields and helmets (spellcasters should get spellcasting failure from this!), but are instead using more magelike weapons such as staffs, slings or ceremonial maces.
The cleric/mage has a vast amount of spells compared to any other mage class in the game. This opens up many interesting strategies in the game. As a cleric you have access to many good spells early on such as command, hold person and silence among with the other protective spells. This opens up the possibility to use damaging spells or crowd controlling spells through your magebook, which on a low level caster mostly consists of sleep, blindness, spook, web, stinking clouds and/or glitterdust. The cleric spells complements the mages' spellbook.
The cleric/mage is as good as the gnomish cleric/illusionist since you'll have plentiful of cleric spells along with your wizardbook. Remember to use damaging spells such as Holy Smite and Flame Strike along with mindcontroll such as Mental Domination and Hold Person. You'll also be able to summon powerful Aerial Servants from the plane of air. Summoning the undead will likely not be as effectful as that of a singleclassed cleric, but when you reach level 11 and above they start smashing (especially if hasted and otherwise buffed). This let you use your mage spells more inclined to protection and the various removal spells along with the otherwise awsome magespells of course.
At later levels, the gnome cleric/illusionist will have an advantage of getting 1 extra mage spell per level (level 7-9 mage spells are very powerful!) which of course is slightly better than the half-elven variant. However, I find it more interesting using necromancy spells (e.g. skull trap, death spell and ABHW) aswell as playing as a half-elf for roleplaying purposes since I never play of good alignment. For me the gnomish Pantheon is just too limited and I don't like the gnomish Gods that much. I could argue for a netural good gnome of Baravar Cloakshadow though, but then again, I would have to play good.
Lastly, the cleric/mage opens up many interesting party combination since you're both a mage and a cleric. Being multiclassed slows your leveling progression somewhat, but clericwise this is more than enough depending on your playstyle. I do recommend having more mages in the party.