Alternative Initiative Method

[ComaVision]

Nobody at my table likes tracking initiative so I decided I'd build something in Excel to make the process faster/easier. Since I was building something in Excel, I could make it more complicated without increasing manual tracking. After some messing around, here's what I've come up with:

Initiative count starts at 1000+d20+modifiers
Highest initiative goes first
After your turn, your initiative count decreases by 30
Your initiative count decreases by less than 30 if you have an initiative modifier (currently using 30-[.6*mod])

Implications:
With a high +Init, rolling high could mean you get two turns before a low roller
High initiative modifiers mean you get turns more often (+5 initiative would give you an extra turn every 10 rounds, +10 is an extra turn every 5 rounds, etc)

What do people think? Am I giving initiative too much weight?

EDIT: Changed the initiative count decrease from 20 to 30, making it more difficult to start a fight with double actions.

[OldTrees1]

For a system like this I suggest making the initiative modifier factor in more than just Dexterity. Maybe cut the dex mod in half as well?

Also you will want to decide how fast you want the fast characters to go. If we call the "-0.4*Initiative Modifier" Speed, then a 10 Speed would double the characters turns. If double turns is okay, then you would want to cap Initiative modifiers at +25. 5 Speed would be 133% as fast as base. If 133% is okay but double is not, then the initiative modifier cap would be closer to +13. Etc.

[ExLibrisMortis]

I like the system in principle, but initiative is already a must-have stat, and at higher levels, going first already provides a massive advantage. This might make initiative too much of a priority.

If you change the way initiative is calculated, for example, by allowing various stats to boost initiative (either stacking or providing a choice), or by granting bonus initiative to mundanes (as a stat next to saves, bab etc.), then maybe you can balance it. You definitely don't want a full caster with triple turns though, just because they can cast nerveskitter and feed a hummingbird some elven birdseed twice a day.

[Gildedragon]

If one is feeding a hummingbird birdseed and having it survive one deserves all the initiative count one gets

[Ruslan]

Rolling high means you can sometimes get two turns before a low roller
YMMV, but this, to me, is a deal-breaker. 3.5e is enough rocket-tag as is.

[Anlashok]

Shadowrun has something like that and initiative is basically the be all end all of stats in that game.

[noce]

Most encounters are over in two rounds, three top.
If a player gets to act twice as often than another, the second player won't have much fun, if he'll have fun at all.

[ComaVision]

I've increased the amount that the initiative count decreases per turn to increase the investment necessary to get two turns before someone has gone.

It would now take a +11 Initiative modifier for a 1/400 chance to go twice before someone with a +0 Init modifier.

[Khedrac]

Something to consider:
Improved Initiative: +4
18 Dexterity: +4
Marshal in the party with Motivate Dexterity and 18 Charisma: +4

That's a +12 initiative modifer at level 1.

Higher level the Dex is now 20 with a +6 item: +8 (increase of +4)
The Marshal took the feat Draconic Aura for the senses aura, they happen to be dragonblooded: +3
The marshal also now has Chr of 20 and a +6 item: +8 (increase of +4)
Now at +23 at level somewhere between 8 and 15 (goes up again at 16)

If someone is willing to play a support character (and a marshal makes a better diplomancer than a bard - skill focus diplomacy is a bonus feat at level 1) then it is trival for the rest of the party to rocket tag initiative out of the reach of anyone else.
Your proposal makes this ability go from overpowered to game breaking.

Personally I have a real problem with the marshal - and it is motivate dex that is the main problem, the major aura are much better thought out than the lessers.

Edit: your modifications actualy do balance this out to a fair degree, but they then make it so unlikely (normally) that the comment "why bother?" has to be made.
However, I do remember a few abilities which modify your initiative by a number during combat, something normally a real pain to adjudicate - your proposal does make them work.