Alright, I know that most who read the title will go: "PVP (Player vs Player) games? In RPGs?! NO WAY!!!"
Yes, yes, I know. Many advise against doing PVP in RPGs, arguing that clubbing GM-controlled Goblins is better for team cohesion than bashing each others' skulls in. I used to belong to that crowd, but recently, on Roll20, I have seen a couple of attempts to run a game based on the holy grail war from Fate / Stay Night.
I immediately fell in love with the idea. For those who are not familiar, the holy grail war is the main plot device in a visual novel called Fate / Stay Night. The main idea is that 7 magicians (called masters, who live in our time) each summon a servant, which are heroes (both real and legendary) from ages past. These 14 people then fight each other to the death, until only one team remains (one magician and one servant), which are then awarded the holy grail, an omnipotent vessel which can grant any wish.
I would like to run a campaign like that myself and have been trying to come up with a good way to do it. My initial instinct is to have 14 players, a map of the traditional city where the holy grail war takes place, and a random starting location for each of them.
Communication within a team is, of course, hidden from opposing teams (unless they are standing right in front of each other). My main gripe now is: How do I deal with combat? The existing rule sets I looked at (I am kind of a newbie, so correct me if I am wrong) were all lacking for that. I personally love the Cypher System from the Monte Cook games, but they are absolutely useless for engaging and interesting combat between players.
Thus, my question: Is there a good combat / RPG system out there, focused on round-based and engaging player vs player combat?
Narrowing: As some have mentioned in the comments, my description thus far does not really narrow things down. So here, in approximately increasing order of importance, is my list of things I think a "perfect" story-driven PVP system should have and do. The most important item is the last:
- Encourage interactions between PCs
- Allow NPC interactions
- Leave enough room to tell a story and to drive a plot
- Allow combat with NPCs, when necessary and appropriate
- Allow and encourage combat between PCs in a way that doesn't make the outcome of the battle trivial or deterministic
- Gives a level system that establishes clear divisions of power (because: Servants outpower any normal human being by a huge margin. A regular human can never beat a servant - Character level or some other attribute should reflect that)
- Allow and encourage round-based actions, both in combat and in-between (the only sensible way to pull this off, in my opinion)
- Have a points / stat system that reflects a character's strengths and weaknesses. Such as: Some servants have strong sword fighting skills, but cannot cast spells or know nothing about magic. Other servants would be pure wizards (glass cannons, if you will). The same goes for the masters that summon the servants. Some kind of stat system should reflect that, and have an influence on the outcome of battles (i.e.: If two otherwise equally-matched servants fight each other, but one servant has a higher sword skill than the other, the stronger servant should have an advantage (but NOT a guaranteed win!)
- Have a spending system. In particular, in the original visual novel, a lot of time is dedicated to explaining that mages have a source of power (mana), which they can draw from their surroundings and use to cast spells. When mana is expended, it takes time to replenish, meaning that spells cannot be cast ad infinitum. Players should have a limited resource to cast their spells.
- Allow pre-defined spells. Although I am trying to avoid typical things like: "Player A casts magic missile", certain masters / servants have special spells which they can use. The system should allow this.
- The system should support classes (the original holy grail war distinguishes seven servant classes, and of each class, only one servant is summoned in one grail war. Each class has special attributes and skills, which always ensure an unpredictable battle and that each servant can win the war, even if they are weaker in some aspects than their enemies)
- The combat system should be die-based (otherwise, the outcomes become deterministic)
The combat system should allow flexibility. This is, for me, the most important point. What I absolutely want to avoid is a D&D-style spamfest with fixed skills and spells which have pre-determined damage, hit rate, etc. Ideally, I would like to make the battle itself a story. In other words, I need a system that allows me (the GM) to use the player's choices and die rolls to weave a story such as the following: Player A is a lance user and decides to attack player B with a direct thrust. He throws his die to determine the outcome and the damage. Let's imagine the die roll goes very bad. Player A therefore not only misses, but loses his balance, leaving an opening for his opponent (making the opponent's strike easier, for example).
To be specific, my problem with D&D is due to three major issues: First, how each round is supposed to represent exactly 6 seconds. Second, the strictness of rules, such as Initiative rolling (a hindrance at best in my use case). Third, the duration of certain effects. It's a lot of rolling and strict tracking of details that are the wrong kind of detail for my needs. I need more flexibility. I need the ability to tell a story in combat, not to be bogged down by an infinity of dice rolls. That's why I rejected the D&D system. But if you think I'm wrong and that it works, I'll welcome such an answer.
I hope that this narrows things down enough. If my shopping list of desirable system traits is too much to ask, would you know of any system that approximates this enough that I could twink and modify it to fill my needs?