In my current system, every action is a skill check, even in combat. Every attempt is
d20 + skill vs. a flat value or an opposing roll. Fixing a robot or destroying it, stabbing someone or sticking them with a needle-full of adrenaline, it's all a skill check. Everything is done with a d20 and I've managed thus far to avoid all other dice, which is a major priority in this system.
That said, I'm having trouble figuring out how to handle thrown weapons. I would prefer to handle tossing a grenade and throwing a knife with the same skill, but I realize that they are very different actions. I'm not sure what methods have been developed to handle throwing/tossing in other systems, and I'm pretty sure D&D 3.5 and 4E don't cover tossing at all.
I would appreciate any ideas or examples of how this problem has been solved before. Even an idea that doesn't work 'as is' might be inspiration for a mechanic that fits perfectly into my ultra-light combat/skill system.
Note: A character's Thrown score is equal to their Balance modifier plus the number of points they've spent on their Thrown skill. This is similar to spending points on Acrobatics and adding your Dex in D&D 3.5. Additionally, the skill only determines the chance to make the hit. Damage is not skill-based and an existing part of the system already covers it.