So, thanks to my recently rekindled Doctor Who obsession, I downloaded Time Lord, the last official Who RPG.

The die mechanic is, well, a bit unusual.  It's based around the concept of "beat the difference".

You take the character's attribute and skill (ranged between 1 and 6), add them together, and then compare them to a difficulty, between 1 and 10.

If the character's total attr+skill is less than the difficulty, then you subtract it to get the difference.

You then roll 2d6, and instead of adding the dice, you subtract the smallest die from the largest, and this result has to beat the difference to succeed.

It's simpler than it sounds when you think about it, that's just how it's explained in the book.  In practice you don't really need to bother with finding the difference, you could just as easily add the die result to the character's atr+skill and compare straight against the difficulty.

I think the idea though is that if the GM knows about certain rolls and who'll be trying them up front, he can pre-calculate the difference and just tell the players what to roll over.  The game was originally written under the assumption that all the players would be playing pre-gens, namely the Doctor and companions, so all their skills and such would be printed right in the book.  Chargen rules weren't even included in the original print version, they were an addition to the Internet release.

Still, it's a bit odd, and definitely a unique mechanic, one I've not seen emulated elsewhere.

Way too much work for such a seemingly simple mechanic. I'd probably read it, say "huh?" and pass on the game entirely.

Quote from: James McMurrayWay too much work for such a seemingly simple mechanic. I'd probably read it, say "huh?" and pass on the game entirely.

Like I said, it's simpler than it sounds.  You can ignore a whole step of the process, and it's basically just a way of rolling "attr+skill+1d5".

Exactly, so instead of grabbing a bunch of seemingly random factors and throw them together, tell the players to roll attr+skill+1d5 (or 1d6 to make it even simpler). It strikes me as a mechanic that went out of its way to be different just so it could be different.

I had an idea for a mechanic where the goal was to get as close to the target number as possible. It was technically "roll over", but if the game used d10 and the target number was 1, rolling a 10 was a really, really weak success. I just never got around to working out how modifiers worked

Edge of Midnight requires both an attribute and skill roll in order to succeed at a task.  If either fails then it's just a partial success, limited by the failure.  I thought it was kinda neat, but it was very different for me.

I agree that the Timelord mechanic seems to have too many steps for most folk.

Actually, the Die minus itself is not that uncommon. I can name four systems off the top of my head that use it (now....).  The rest of it isn't that odd, but the presentation given makes it hard to follow...which I assume is an artifact of the book.

Really, this is rather like Feng Shui when you think about it, just written backwards.

Quote from: WilI had an idea for a mechanic where the goal was to get as close to the target number as possible. It was technically "roll over", but if the game used d10 and the target number was 1, rolling a 10 was a really, really weak success. I just never got around to working out how modifiers worked

Check out Unknown Armies, it does this and it does it well.