Loadfix allocates a memory block of the specified size (in kB, default is 64 kB) in lower memory, making that memory unavailable to programs, and also making subsequently executed programs load at a higher memory segment.

It's sometimes necessary for programs that are buggy with regard to how they allocate and otherwise use memory. It's not so much that the programs were poorly tested, it's just that the bugs emerge only when then memory environment differs from the environment that was used for testing.

When DOS first started allowing portions of itself to be loaded into the HMA, more low memory became available, and bugs in programs started emerging. In DOSBox, the emulated DOS uses even less lower memory than real DOS loaded into the HMA, which can expose the same (or even additional) bugs.

As an example of a smart (i.e. not random) way of using loadfix: let's say you have a game that was released around the time of DOS 3.3. It can be useful to boot that DOS and see what segment a game loads at. Then in DOSBox you make a loadfix allocation so the game loads at approximately the same segment, thereby greatly reducing the chance of triggering any memory-related bug.

Thanks Ripsaw, so I guess it's use mainly applies to older (i.e. pre-DOS 5 games). Though it may also be useful for some newer things that have trouble with excessive free memory.

Do we have any inventory here of games that need LOADFIX?

It's hard to talk about a list of such games...
I used to use loadfix to run Operation Wolf on windows 98 computers and on older DOSBox versions (I can't remember which ones exactly) both according to the configurations of the computer/emulator