This is based on a short film I'm in the process of writing, but I'm still not sure who's gonna win it. Here are the participants due to some time/space, er, ******, in order of their appearances.
Gordan Freeman: The "Half-Life" Series
After waking up from a mysterious, er, nap, with his dreams invaded by The G-Man, he found himself carrying his gravity gun, his trusty crowbar, and a .45 Revolver, he finds himself walking down a mysterious hallway, leading to the arena...
Solid Snake: The "Metal Gear" Series
Out of the corner of his eye, Freeman sees a blur run past him in the same hallway he just came from, up to a staircase. Gordan runs over to look up the stairs, and it's too dark. He turns on his flashlight, and sees only a cardboard box of a flat surface, reading "NO PLACE FOR HIDEO." So, Gordan walks away, and the box begins to walk up the stairs again. When he gets to the top, a balcony overlooking the arena, Snake takes off the cardboard box, lights a cigarette, and examines Gordan walking around the arena.
Sam Fisher: The "Splinter Cell" Series
Just then, Snake hears a "wrrr" sound on the balcony, and then turns to see a green light in the darkness. Just then, both Snake and Sam pull out suppressed handguns, and Snake has a red laser pointed in the center of the 3 green dots in the darkness...
Master Chief: The "Halo" Series
The badass from the future has entered the arena while running away from a literal army of Covenant, which damaged his sheild generator (in the interest of fairness), armed with a Battle Rifle, and Assault Rifle. Now, he steps into the arena's lower floor, spotting Gordan Freeman. Gordan points his Grav Gun at him, Master Chief, his Assault Rifle...
And some more parleying happens, and then the battle begins. The question is, who will be the one left standing?
Master Chief of course, he's the Chief! What's a few lousy terrorists or alien invaders against the Covenant?
Solid Snake would be sneaky and cool, but in the end, he'd die from fox-die.
Master Chief has his armored removed, and runs off while GORDON, not Gordan chases him with his trusty crowbar.
Sam Fisher just watches the battle from the darkness, and should someone team up with him, he'll double agent their asses and win.
Big MC's sheilds were removed, not his armor. We ruled out his sheilds because we believed they would be too powerful, but because of his armor, he still is the best in terms of defense.
I've already given you the situation, Snake has already spotted Fisher.
And we're not counting the Fox-Die virus.