Half orc is one of my favourite foe, smart and brutal, the only advice is to play them as they were your characters and not just a bunch of cannon fodder, your party will hate em. M20 stats follow the basic rules, HD is a D6.
HALF ORC OF THE WILD COAST (NE)
HD2 +4 (10 hp), AC16 (chain and shield), By weapon +5 (1-8 +2 longsword)
The long wars generated many orc’s mixed offsprings, considered outcast by everyone they begun to group and live togheter as a race, regardless of the other half of the mix. Usually they form small mercenary units that serve anyone can pay as scouts and elite units. The Scarlet Brotherhood uses many of them. This half orc is smarter than his cousins, he’s higly civilized for their standards and can be a deadly foe since he’s very well organized. They can also be spies and killers, but their appearence, closer to orcs than to the other half, keeps them within the Wild Coast region.