Hi -- I hadn't heard of the play with anything seminar before but I'm starting up a play with anything campaign and have done two d20 Modern Characters in a D&D 3.5 Adventure one-shots that went well so I'm going to track what issues I've come up against and what resources I'm using to manage those issues.
First, the one-shots:A while back I ran two one-shots for two players -- I took off-the shelf D&D 3.5 one-shot adventures and without any modification had the players roll up d20 Modern characters of the approximate level listed in the adventures.
There was a keen chainsaw wielding everyman and a spec-ops shooter mowing down zombies in a church and it went pretty well. The two issues were that the D&D monsters seemed to assume that they'd get into melee range with the players which didn't happen much because the shooter was a very effective ranged fighter. This was before the Warlock existed but I'd assume the adventures would've had similar trouble with an optimized archer, really. The second adventure, which featured two Ogre Magi as the climactic battle was much more suited to the d20 Modern characters but again, the monsters lacked ranged staying power which was the base of their downfall.
So, from this experience I gathered that tactically, encounters need to take into account the improved ranged fighter options given revealed by including the d20 Modern source material.
Now, the Campaign:Melding worlds -- The campaigns I run tend to handwave away anything that seems implausible and my players usually run with it just fine. Just making sure the players understand that they're supposed to be working together gives them the impetus to concoct the reason to work together. That's how I intend to deal with the side-by-side existence of fantasy and mundane worlds, really, just ignore what makes is "logical" and keep to the parts that make it fun. With this in mind I intend to have sections of the world where d20 Modern is the standard and sections where D&D 3.5 is the standard and it's harder to find equipment or possibilities of the other type. However, I also intend very much to merge these two worlds together and use them to enhance each other.
For example, some encounters and creatures I'm considering:
Power Suit Goblins -- Take a d20 Modern Mecha, make it out of Darkwood and place a goblin or two inside.
Zombie Survival -- Make ammo scarce, make the players work for their rest and downtime, see if they can find synergy in the two sides of the coin to survive
Wealth or GP -- This was something that immediately became apparent as a prospective problem since d20 Modern and D&D 3.5 assume two different economic systems. Since I'm already handwaving away the duality of the world I can simply choose one and stick to it but then how do I convert one to the other? How much GP is an AUG worth? What's the purchase DC for a flask of Alchemist's Fire? I figured it'd be easier to use Wealth checks in place of GP than the reverse and as far as I can tell it'll be a lot of determining the purchase DC for something similar in d20 Modern then giving it a +/-[0-8] DC modifier for being easier or harder to find in the part of the world the players are in. Also, when I need a ballpark figure I did find a useful resource, the
Frilond Currency Converter. Someone already took a campaign and created a GP to Wealth Check DC mapping which seems to be fairly on target for magical items that are duplicated between d20 Modern and D&D 3.5 such as potions and wands.
Therefore, I'm going to go with Wealth checks and see how it works out.
Feats and Issues of Competing Cost -- One of the glaring problems that is probably indicative of a whole slew of issues I saw was the existence of Archaic Weapon Proficiency in d20 Modern. It's effectively equivalent to Martial Weapons Proficiency but is only one feat. Sure, being able to get MWP for the cost of a single feat isn't all that impressive from a CO standpoint but it shows that one system or the other will have something that's considered a discount and hard to pass up. (Magic use is another obvious similar issue -- why choose d20 Modern Mage when I can just be a Sorcerer?) So how does one handle this? Again, I think I just need to make it more or less difficult to obtain and prevalent depending on what part of the world you're in. Thus I full expect to have Ogre Magi wielding M60s and the Mage advanced class will probably be totally shunned. Will this result in more powerful characters on average? Yes, of course. This power difference will be mitigated by two factors -- First, I'm a better Min/Maxer than my players this time around, since they're all noobs, and second I'm still the DM and that still means I get to control the overall level of resources in the game. If I make ammo scarce then it's harder for the AUG to be more powerful than it needs to be. It makes every shot count. If I'm stingy on rewards then it means it's tougher for the players to just roll around in a tank and run over piles of kobolds.
Skills -- When you add up two systems, both of which have a large skill set you'll make it even more difficult to make positive skill choices. Therefore I'm going to test out a skill system modification: Synergy categories. The basic idea is one that's been used in Paranoia d20 -- group up certain skills into one super-skill. So Balance, Climb, Escape Artist, Jump and Tumble will all be considered under the Acrobatics skill set but they'll also be their own skills. You buy ranks in Acrobatics at 2:1 and you apply your ranks in Acrobatics as a Synergy bonus to all the skills in the Acrobatics skill set at 1:1 for class skills and 2:1 for cross-class skills. However, your base ranks in the particular skills are still the official "ranks" score for that skill for things like fulfilling Prestige Class requirements. Yes, this could allow someone to get a +385 jump modifier if they wanted but again, I can work around that as the DM.
So far these are the only major issues I've seen that are glaringly obvious. I'm currently fully into world-and-campaign-building mode so as things come up I'll expand on this. Also, I invite anyone to propose theoretical issues or cases to be considered, asking how I would deal with some situation or to propose solutions to any problems I or anyone else comes up with. I'll try to keep this updated as the world building and eventually the game progresses.
Thanks,
Zero