Lanefan
Victoria Rules
What makes the biggest difference to overall combat length, all other things being equal, is complexity of opponents. A party taking on a dozen Giants doesn't (usually) take all that long. A party taking on a dozen adventurers takes for-nearly-ever; the all-time record for what I've DM-ed was a large and powerful party assaulting a stronghold full of powerful levelled foes - about 50 participants in total, not including summoned monsters etc. That nightmare took 3 complete sessions to resolve; at one point a single round took 2.5 hours...and that's using a 1e-based d6 initiative system!
Plotting the bad guys' tactics in advance doesn't help very much unless you know exactly what the PC's are going to do throughout the combat, as to be at all convincing the bad guys have to be able to adapt to how the combat is going.
We re-roll initiatives each round, and find that doesn't add too much time except in the simplest of combats.
Side note: the longest combat by rounds I've ever seen was a single character fighting her own clone one-on-one...the AC far outstripped the ability to hit...38 rounds later, the clone won.
Lanefan
Plotting the bad guys' tactics in advance doesn't help very much unless you know exactly what the PC's are going to do throughout the combat, as to be at all convincing the bad guys have to be able to adapt to how the combat is going.
We re-roll initiatives each round, and find that doesn't add too much time except in the simplest of combats.
Side note: the longest combat by rounds I've ever seen was a single character fighting her own clone one-on-one...the AC far outstripped the ability to hit...38 rounds later, the clone won.
Lanefan