New "default_attack_skill" field should now work for unique chars and mobs.
Random chars should be different, it might be a good idea to add the same to combat related base traits and draw it from them. Rules are the same as before but I am considering changing them to make sure that this default attack is always available. We can force it to only require VIT and crash the game if someone puts up MP/HP attack as default. It will make my job writing AI that much easier, because I could always depend on one attack being there.
Now that I wrote the above... it would not matter cause you're making new traits to resist any damage... so I cannot count on anything. I guess I'll just add 50 turns limit to logical combat and force draw after that.