The HP bar is your life or health because hp stands for Health Points.
When fighting and you're opponent attacks you, subtract the amount of HP stated in the skill or weapon from your HP and put the remaining amount in parenthesis at the bottom of your post.
The MP bar is your energy pretty much. MP stands for Magic Points.
When fighting and you use a skill that requires MP you have to subtract the required amount of MP from the amount of MP you have then put the remaining amount of Mp you have in parenthesis at the bottom of your post.
The Strength bar is your strength(obviously). This bar is for anything that seems like it would require physical strength.
When fighting and you're using one of your weapons or a skill that requires an amount of strength, you have to subtract the required amount of Strength from the amount that you have. Then you put the remain amount of Strength that you have in parenthesis at the bottom of your post.
Keep in mind that you all are being let off easy. We could always add a system that would determine if you hit or miss but we're allowing the members to determine it themselves. If too many people say though that they're hitting or dodging, a system will be put into play.
Again, do NOT godmode.