There are six editions of Call of Cthulhu. Really? I've played CoC over the years and honestly, I can't tell you what's changed between those...new professions? skill consolidation? Looking at the versions, I'm pretty sure a person time-traveling forward with a CoC 1e character sheet could sit down and play in a game run today. The cell-phones at the table might throw them. And the varieties of Mountain Dew...sorry "MTDew."
In my list-post about edition changes I talked mostly about those our group balked at or changed our play significantly. Another blog, The Iron-Bound Tome, independently hit on the same topic- with an even more in-depth examination of their group's shift. As well, after I posted my list on the Geek, user Aramis added an incredibly comprehensive overview of the Traveller and GDW House rules family trees...making me thankful for the minor problems and throw-away books I'd had. Paranoia, a great game went through many changes as well. I only ever played the first edition with its innovative skill tree system. But I understand that later editions made fairly drastic changes to tone and mechanics. That being said, many edition changes have worked for me- I mentioned being pleased with the various changes to the classic World of Darkness lines. As with CoC, I never had the feeling that the changes invalidated earlier forms. They felt like minor adjustments and fine-tuning. I couldn't begrudge those.
Of course, now we have access to high-speed commentary, a noise-machine of insight, and the ability update FAQs daily. The blogger Geek Ken points out WotC behind-the-scenes changes to the 4e engine- creating constant new editionS. I guess if you're trying to emulate an MMORPG you might as well have bizarre weekly updates. Games can easily get changed and fixed after publication, especially if they're purely electronic. One the one hand that's cool, on the other hand I'm not sure I want to be that engaged. But then again, I'm not the target audience for that. I'm one of those fairly picked veteran gamers who isn't looking for a game with that kind of crunch and electronic interactivity. We do enough tweaking and rules changes in house that I'd be a little nervous about bringing someone in who has played the system or even trying to run some of these games at conventions. After I wrote to my wife, I mentioned Rolemaster and that's we'd enjoyed playing it at the time. "We never played Rolemaster," she replied "we played some bastardized game that stripped out things like complex initiative, experience calculations, spell limits." And she's right- and I have to wonder how much one group's version of a system resembles another, especially with complex games.
THE REQUIREMENTS OF REVISION
If you do a new edition of your role-playing game, I expect the following things:
An explanation- IN THE BOOK- of the differences between this and the previous edition. It doesn't have to go at the front, it can be in an appendix. It doesn't have to justify those changes- just tell me what the big differences are. If you don't acknowledge the existence of a previous version IN THE BOOK ITSELF then I can only assume A) you haven't made any real changes and you're screwing me out of my money and/or B) you don't care about bringing along players of the previous version...Games Workshop.
Rules for converting characters between the two editions. These don't have to be in the book. You can have these online, but you'd better have them. Just saying conversion should be easy is a cop-out.
I've rarely had to do that kind of conversion, but when I have to I want some help. The most recent example was moving characters from M&M 1e to 2e. Somehow my players had all managed to pick powers that didn't translate over directly or required major jumping through hoops to get to work. Also, when you do come out with a new edition of a game, please leave electronic versions of the previous edition material for sale. Don't be awful and remove those from circulation to encourage players to "move on."
ON CHANGING RPG HORSES IN MID-STREAM
On the other hand, sometimes transitions between games can be self-imposed. A couple of times we've dealt with inter-system conversions. One difficulty is lies with different games have different base-level assumptions. In the 1990's I'd been running GURPS Fantasy for a while- several campaigns on the same continent of my game world. GURPS characters exist within a fairly narrow range- with differences usually based on quality of skills and slight variations in stats. At the same time, I'd been playing in a couple of Rolemaster campaigns. Each time I sat down, the chrome of that system sang to me: tons of distinct weapons, the most obscure classes, charts, criticals, thousands of spells, open-ended percentile rolls. At some point I decided that I would run the next campaign in that same setting using Rolemaster. And of course I used every supplement available, including the over-powered Elemental Companion.
Let's say that didn't turn out so well. What had been a kind of heroic fantasy campaign, with magic and monsters as significant threats suddenly blew up. It was like dropping Doc Savage into a realistic Call of Cthulhu campaign or Elminster into an Ars Magica game. It reshaped the tone, with the kind of power players could throw around. Where magic had been interesting before, it suddenly became commonplace to fit the needs of character building. I'm sure I could have done more to keep that in line, but it hadn't occurred to me before we started playing. I hadn't realized the implications of level-based characters running around in a point-based world. Eventually I decided to switch systems, going back to GURPS.
There is no good or consistent way to do that. It ended up an absolute mess- trying to model characters such that they still felt powerful in their GURPS versions. The game crashed and burned pretty quickly.
I hit a different reason for rules switching came when we played a few sessions of Fading Suns. The group had been playing through several systems, mostly variations on Storyteller. I opted to use the base mechanics in Fading Suns. If you're not familiar with that, you roll a d20 under a target number. That number's based on stat + skill. You want to roll under that target, but then you determine success by having the highest possible roll under that. Plus you have several other modifications and considerations to that mechanic. For a group used to just rolling low (for GURPS), rolling high (for Rolemaster), or just counting successes (for Storyteller) suddenly every roll required counter-intuitive reading. I'm sure we would have gotten the hag of it eventually, but after two sessions of players getting frustrated and things taking twice as long as they should have, I stepped in. I scrambled up a quick Storyteller adaptation to that and rewrote everyone's sheets. After that players seemed to enjoy the game much more.
What did I learn from that? I learned system does matter. Ideally you ought to be able to pay anything with a game, it ought to be fairly transparent. But that's not true- and the reasons may not lie in the mechanics alone. Systems determine optimal builds- and the more specific rules there are, the more optimal builds those become. The designers of the upcoming Adventurer Conquerer King rpg have a really excellent piece on the phenomena. In Champions*, for example, players really needed to have at least one point of resistant defense. That one point allowed players to apply their full defense to the Stun done by a Killing Attack. Otherwise, they could get take out very easily. So you have a world of superheroes where everyone has to wear a little bit of armor...which would explain the comics of the 1990's.
Likewise, DC Heroes had an interesting idea, but one that in play caused weird problems. In that game characters have three set of stats- Physical, Mental and Magical. For each you had an effect value, a resistance value and a HP value. That's cool- it means you can have a group with several different foci and areas of expertise. In play, however, it meant that players did damage on each track separately. So a Brick, a Mystic and a Mentalist will all be doing different kinds of damage. In practice, if a target had a weakness, the person with the right attack would take them out. The same thing held for the PCs- so what you saw over time was everyone buying those HP and resist stats in parallel to avoid those problems. Rather than creating specialization, the system encouraged and rewarded generalization.
And sometimes you don't see these things until you get well into play. That's another danger of doing game conversions or edition switching...what if you do all of that work, spend all of that money and discover there's some fundamental flaw? Not a house-rule-able thing, but something basic to the game. Is that why we need online DDI-style services to fix our game on the fly? I'm skeptical about that given how many edition shifts I've seen "fix" things that weren't broken.
*Note that I'm talking about Champions up through 4e...since I have no idea if this has changed in 5th or 6th edition...