One of the hallmark gameplay features of most shooters is that after you have finished firing a few bullets or survived an exchange with a rival player, you reload your magazine, regardless of how much remaining ammunition is left in the clip. From a realistic perspective, it's ludicrous behaviour, but that's why we love video games, as this 'wasted' ammo is just magically fed back into our reserves to be used later down the line.
This is also a key feature in Counter-Strike gameplay, and has been for years, but no longer. Valve has revealed a new update for Counter-Strike 2 that will mean that when you discard a magazine, and remaining ammo is simply discarded with it, making reloads immensely more important.
Valve's reasoning behind this actually rather massive change to CS2 is as follows:
"When you reload in CS2, the leftover ammo in your magazine is dumped back into an essentially endless reserve supply. And so the decision to reload has never offered significant trade-offs—in a safe position with enough time, you might reload after firing a single bullet, or half a mag, or after firing down to empty, and the rest of the round would be unaffected.
"We think the decision to reload should have higher stakes, so in today's update reloading has been redesigned. Now, when you reload, you'll drop the used magazine and discard all of its remaining ammo. Instead of 'topping off' your weapon with a few bullets, a new full magazine will be taken from the reserves whenever you reload.
"How many reserve mags will each weapon have? Most have gotten a three clips fill-up, but some weapons will have less to reward efficiency and precision, or more to encourage spamming through walls and smokes. Keep an eye on your reserve supply!"
This change also comes alongside map guides in competitive matches and the ability to join friends directly when in custom games, but even if these are welcome improvements, many will likely only be concerned about the reload change for the foreseeable future.