This one is a bit hard to describe, but I like a variety of mechanics that acknowledge HP loss as a possible thing that can happen (rather than, say, rewarding you for no-hit runs).

One example is when a game balances between giving you decent ammo, and decent healing items. Sometimes shooting every zombie is the better play because health is scarce. But when ammo is scarce and health is plentiful, it may make sense to run through 3 zombies taking only a few bites.

There's also HP feedback loop systems, where it's still bad to get hurt, and you're better off avoiding it, but when you DO get hurt, you build up some kind of meter that allows you to use that as a comeback. This might include things like a super-attack meter that builds when you're damaged, or faster attacks that only come from low health or broken armor.