I cheated on the original Halo (PC, online capture-the-flag) because I really sucked at it compared to everyone else, which made it unbalanced and therefore not fun to plan (not saying it was right, just filling in the understanding you were asking for).

I didn't look into aiming bots, but I did figure out how to edit the resource files to make the walls transparent so I could camp the flag and see players coming for it long before I was supposed to.