> The best solution is probably to store the current HP as a percentage of the max, because then you never have to rescale it in the first place.
Doesn't this solution make the more common calculations more expensive, complicated, and error-prone to make one rare calculation easier? It seems like far more of the operations on the unit's current HP will be "gets damaged by X hp" or "gets healed by X hp", both of which would require the equivalent of the above conversion to establish a result.
If you’ve changed HP to a percentage, why wouldn’t you also change the damage and other related numbers (such as damage reduction and so on) to percentages as well? Nobody would be dumb enough to store them in different units and then convert every time they manipulate them.
> why wouldn’t you also change the damage and other related numbers (such as damage reduction and so on) to percentages as well?
Because a sword might do 5HP of damage, not 10% of anyone's damage (whether they've got 50 or 5000HP). Otherwise, hit points are meaningless: 10 attacks with a 10%-damage weapon kills a lowly serf or a mighty dragon.
And because damage reduction might reduce a fixed amount of damage from an attack. Etc.
Obviously a dragon doesn’t get damaged at all by a puny little sword. You can’t just say that hitting a dragon with a sword a thousand times would kill it, when none of the attacks can get through the dragon’s armored hide. On the other hand, it will die immediately if pierced by an arrow provided that arrow hits the one spot where the hide is missing a scale. The dragon has 100% DR, except in that one spot.
> Obviously a dragon doesn’t get damaged at all by a puny little sword. You can’t just say that hitting a dragon with a sword a thousand times would kill it, when none of the attacks can get through the dragon’s armored hide.
Doesn't this solution make the more common calculations more expensive, complicated, and error-prone to make one rare calculation easier? It seems like far more of the operations on the unit's current HP will be "gets damaged by X hp" or "gets healed by X hp", both of which would require the equivalent of the above conversion to establish a result.