Party of 9

[DEFCON 1]

In order for there to actually be tension during battles without there being way too many hit points spread around the table on both the PCs and monsters sides to grind through... I'd suggest that you HALVE every PCs *and* monsters HP.

The PCs might gripe about it a bit... but honestly, they will appreciate it more when their attacks (which will come up half as often as they would if there were only 4 others at the table) actually have a more measureable effect. Halving a 90 HP monster to 45 means that a single swing might very well bloody it... so it at least seems as though they are doing something meaningful with their one attack that comes around to them every five minutes.

As far as halving their own HP... nine full HP PCs requires 9 full HP monsters to be equal challenges. Do they really want to grind that long just to have battles feel like they are a potential risk? Halving their HP makes each monster swing more meaningful as well.

The positive side is that it's easier to halve HP numbers than it is to double everyone's damage. So that saves time even more.

 

[Garris]

Note that with 9 players another problem experienced will be one of synergy. Bonuses/penalties will stack fast. Anything that affects "all allies in x squares" or "until the end of your next turn" will basically double in length from the assumed default.

As has been pointed out, Elites will die in a (slightly) smaller amount of (combat round) than a Standard would with 5 players, and Solos will die like Elites.

Be exceptionally careful of the "stun" condition. It will ruin someone's day in this game.

 

[aco175]

Some of these ideas are good for any play.

One of the things I do is have the players role for damage on them from the monsters, you could even have them roll to hit with this many players. You can have a few helper/assistants role to hit as well.

I have one player track initiative on a piece of paper, but I like having someone track it on a white board better. He could even role for the next fight between encounters.

I have heard about rolling to hit and damage before play and crossing off as you go, for instance each monster you would have 10 hit and damage rolls already done. I somehow feel this is weak, or cheats a bit, not sure why. It does sound like it would speed things a bit, esp with brutes and soldier monsters.

 

[keterys]

Just average all damage. When rounding, round to the nearest even number so it's fair (instead of truncating). Do it in advance, so no math has to be done on the fly in that respect.

Switch to two tables. Seriously. Two groups of five (1 DM + 4 players) is great!

Be very wary of halving hp, because it's very likely to get anyone focus fired on killed very very rapidly. Monsters or PCs. Five artillery attacking a character can already drop them in one round, but make them effectively deal double damage while there are twice as many of them and... messy.