“Fight! is a cool game that does what it sets out to do. Too bad the rules only allow one-on-one fights.” This particular comment, or some variation of it, is something I come across a lot when I find people talking about Fight! online. It’s a little frustrating because it’s not true. Furthermore, I’m not even sure where the idea comes from.
For those looking for it, the rules for multiple combatants are in the core rules, pages 128-130. These are to be distinguished from the rules for team combat, which usually features variations of one-on-one combat, found on pages 152-153 (and significantly expanded in Round 2). Fights with more than two combatants are a little more complicated at first, but really, once one gets used to using the band grid suggested in the rules, fights are not only not that much longer, but are very easy to visualize.
The dynamics of combat change in interesting ways. The rules for Hit Stun keep combat moving at a decent pace, as it is unlikely that all the combatants will get to act every turn. Ganging up on an opponent has the same advantage as focus fire in any other RPG, but there is actually an incentive for each fighter to attack a different opponent, so as to lock up all of the opposing forces with Hit Stun.
All in all, I don’t find multiple combatant fights to be any more difficult to run than any other tactical combat-heavy RPG out there. Personally, I think it plays better than multiple combatants in the old Street Fighter game.
Here is some advice on running multiple combatant fights so more players can feel confident running Fight! as a more traditional RPG with everybody involved at once. First, know the rules. Fight! plays fast enough but it does require the buy-in of at least the Director knowing how the game is supposed to be played, and this is especially so if multiple combatants are involved. Second, set up a chart for the fight on a piece of paper. Include columns for each of the combatants. Each turn, record the character’s Initiative and Control. When the character acts, or is deprived of his or her action, cross their numbers off the sheet. If Hit Stun reduces a character’s Control, but not to zero, cross off the rolled Control and write the new Control. Thus, the Director (or whoever is designated to control the sheet) can just look at the highest Initiative that has not yet acted to see who acts next. Third, try to avoid Environmental Hazards. Adding a single one is not too difficult to manage, but more than that becomes very difficult (albeit not impossible) for multiple combatants. (I wish this was not the case, as I love Environmental Hazards a lot, but I have yet to come up with a better method short of using an actual battlemat for combat, which I refuse to concede to.)
I like fights with lots of fighters because Special Moves interact in new ways when there are more combatants around. Elements like Mobile, Increased Knockback, Ranged, and Hurl gain new value. Throws happen more often. Bottom line: give it a try and see that the rules can handle multiple combarants just fine.
At the moment, my largest combat was this: 5 PC Fighters supported by 10 Thugs against a faction of 3 NPC Fighters supported by 20 Thugs against a faction of 30 Thugs with guns. 68 combatants in a single fight. And I resolved it in play-by-post, no less. 
