Internal Consistency In Video Games

In another one of their "analysis" editorials, Gamasutra examines the importance of internal consistency when a developer is creating a sequel-heavy video game franchise. BioWare's Mass Effect series is referenced as an example:
The Codex, Mass Effect's version of an encyclopedia or story bible, explains that the weapons originally used incredibly small slivers of mass and fired them so quickly that, in effect, they could never run out of ammo. Imagine each atom as a projective and then sticking a small hunk of metal into a weapon to act as the source of atoms and you get the idea from there.

Essentially, this eliminated the need for ammo of any kind. Instead, the gun would slowly overheat and require you to pause to let it cool before you could fire again.

Apparently, this was chalked up to a bad design decision or was simply considered not as cohesive once other changes were implemented during the interim between the two games. Limited ammo returned but in a fashion that, when explained, makes perfect sense.

You see, the Geth had been using removable heat sinks to get around that pesky need to cool the guns. The player isn't gathering ammo in the game but new heat sinks that were designed to mimic the Geth's technology. This provides a nice solid explanation in the lore while also allowing for the gameplay illusion of scarcity.

In fact, the Mass Effect franchise tends to handle this kind of thing very well. The same can't be said for all BioWare franchises, unfortunately.