I have a fascination with biotechnology, biopunk sci-fi, and a general interest in body alteration that can sometimes border on the horrific. Growing up I was really inspired by Guyver and later in life, I fell in love with the Prototype games as well as mangas like Abara. This lead to recent attempts at thinking about how I would replicate a similar concept with a roleplaying game.

I'm really looking for any systems that might work, any advice or experience you might have on the concept, or anything else that you feel like sharing. Also, I suppose if you are interested you can drop a comment below so I can gauge if this is a good idea or not.

I love Guyver and I've beaten both Prototypes. System suggestions would be Mutants and Masterminds 3e or GURPS 4e.

Maybe M&M. I've never really liked GURPS. Are there any particular advantages to using GURPS?

Double Cross is specifically designed around this premise, though I can't recommend it unreservedly becaus I don't have the book.

Other than that, your idea is essentially a supers game, so most supers systems or BESM will work (usual caveat on BESM: it's very, very easy to break).

I'd recommend M&M over GURPS, myself - though GURPS is by default much more lethal, which may be of interest to you if you want it gritty and bloody. M&M is normally dialled much more to the "hits are more likely to stun you or knock you out" than to "one hit will turn you into a lovingly-described paragraph of gory bits."

I looked into Double Cross and at least in concept, it seems closer to what I'm looking for. The reviews on DriveThru don't convince me of how good it is though. I have to say that I'd prefer a grittier, more lethal game so M&M might not be the most appropriate unless someone has a suggestion on how to get around the "they are just knocked out".

If I were to go with GURPS are there any sourcebooks you would recommend?

I'd recommend at a minimum Supers and Powers for GURPS. Stay away from the Bio-Tech books - those are generally about realistic transhumanism rather than anime-style transformation into a monster. (Which is the problem with using GURPS for this.)

Double-Cross gets very lethal, though what may turn you off there is its focus on relationships and having a humanity system, which is unfitting at best for Prototype and completely out of theme for Guyver.

I think there's rules in the GMG for M&M to make things more lethal. In the corebook, it's possible to simply presume that defeated minions are dead, which allows for humans to be fragile to the point of explosive, but PCs and major adversaries will still generally require concentrated effort and intent to put down. (Which, admittedly, does fit if you want PCs who can regenerate from a single cell.)

I see. Thanks, Ramidel. I'm not expressly trying to railroad people into abandoning their humanity but its definitely not the primary focus of the game. If I were going for something of that nature I'd play Beast: The Primordial. I'll look into the GMG and see what they say but your suggestion makes a fair bit of sense.

I'm considering making the PCs all have a shared "racial" power set to distinguish them from humans and then their traditional power set all reskinned to fit the narrative. I'll play with PLs and see what fits the best.

I am genuinely surprised that no one has yet mentioned the HERO System and/or Champions. You'd want to set up a list of abilities and power suites, but you could basically make the game fit whatever you want out of it. Everything you see Mercer do in the video games can be replicated in Champions regardless of edition.

Heck, I once used 5E Hero to make a spin-off game based on the System Shock games.

It would still be useful to take a look at GURPS Bio-Tech and GURPS Ultra-tech for ideas.  Transhuman Space is also something you could look at.  It uses GURPS 3rd edition, but there are a number of other books for 4th edition, including Transhuman Space: Changing Times and TS: Shell-Tech.  Here's a list of books available:  http://www.sjgames.com/transhumanspace/

The advantages of using GURPS is that allows for high customization and the really nitty, gritty specifics. It gets real crunch when it comes to numbers and what not. It would be pretty high scale as you are to take on military tanks, assault choppers and destroy buildings.

M&M is good if you want it quick and clean. It's pretty easy to build Mercer and James. They do have a lot of powers by the end of it and are a fairly high PL.

Mutants and Masterminds, just make pretty much everything a minion and that ups the lethality significantly.

In reply to Rothos1 (msg # 11):

Marvel Heroic might also work, it's fairly rules-light, but it can be tuned up to get more crunchy if needed. It's narrative-powered underneath, so the system stays pretty balanced without much homework required for the GM. Plus, there's quite a few sources for the system around, and lots of stat blocks for the various powers you'll inevitably want to incorporate into the game.

Thanks for the suggestions. Here is the game that came of them.

link to another game