Pretty much what the title says. I'm about to start BG1 (via the trilogy) for the first time, playing as a fighter/cleric multi-class half-elf, and I was considering whether it was worth investing proficiency points in the one-handed style.

If I can still equip a shield while getting the benefit of the style then it might be worthwhile, but if not then I'll probably look to spend the proficiency points on weapon classes or dual-wielding. The bonuses for investing in sword and shield style (increasing missile protection) don't seem worthwhile.

As a side query, how many proficiency points does this multi-class get (and how frequently) compared to a straight fighter or cleric? I've been researching these questions online but it's hard to find definitive answers.

You have to remember one thing: one-handed weapon style grants AC bonus. Shields grant AC bonus. Work it out for yourself. ;)

Your multi-class gets proficiency points as they level up in a particular class, but since your fighter class is shared with the cleric class, you will not get as many as a pure fighter. In BG1, not many -- probably 2 for your fighter class, and 1 for the cleric. You're looking at level 7 in each class.

Thanks for the info - I guess my question becomes this: do the AC bonuses from the OH weapon style and the use of a shield stack, or not? From your answer I'm guessing not, which really means that the only bonus conferred by that style while using a decent shield is the extra crit hit chance.

Do you know of link that explains in more detail the starting proficiency points for classes and how frequently additional points are acquired?

As far as I'm aware, in effect, they overlap: the greater is used, which almost invariably means shield wins, especially magical shields. Sure:
[url=http://playithardcore.com/pihwiki/index.php/Baldur%27s_Gate:_Progression_Charts#Fighters_and_Barbarians]Fighter[/url]
[url=http://playithardcore.com/pihwiki/index.php/Baldur%27s_Gate:_Progression_Charts#Clerics]Cleric[/url]

When you create your character put 2 proficiency points into slings and 2 into a melee weapon type (war hammer, flail/morningstar or mace), the second point does make the difference.

You get exactly the same proficiency points as a pure fighter of the same fighter level. 4 at start, and 1 every three fighter level. (A straight cleric starts with 2 and get 1 more every fourth level.)

One-handed weapon style only work when you have an empty hand. It does not stack with shield. Sword and shield style may not be very rewarding, but you may not have any place to better spend your points

Thanks for the replies everyone. I've started my game with 2 points in warhammers and 2 in slings. Enjoying it so far.

This should work well against undead!