I am making a text based rpg in c++ how should i make an efficient battle system witj things like hp and attack.

Answer 1

... This reminds me of...

https://code.sololearn.com/cgNuU15zVpos/?ref=app

Looking back now, the code structure may be crappy, but the way the hit points and other parameters are calculated may give you a vague idea how to do stuff. This is fully automated due to the limitations of Code Playground, but it can easily be tweaked into a turn-based game.

Answer 2

How exciting. :D This is actually how I got started with programming back in the late 90s; I use to make online text based RPGs.

As for how you should go about those systems, there are many potential directions you could go with that. Do you visit the SoloLearn Discord server at all? I'd be more than happy to help you sort out how to go about all of it, but there is a lot to explain and would be easier if I wasn't limited by a certain amount of characters I'm allowed to type.