In a thread on the WotC boards, I started a thread about technology on the planes, mostly relating to far-flung megastructures and ramfications of the Kadarshev scale. So since there are people here working on modern planes, I'll ask:
How would magic affect the growth of technology, or vice versa? Would magic influence planar society's Type in any way?
Since planar rulers have control over their layer, would their influence extend to stars or planets in the layer?
Is it possible that Sigil is a ringworld? If so, what would it be encircling?
Are there any future possibilities that would result in a situation similar to The Second Renaissance?
Well, the default d20 Modern game is PL 5, the Information Age. 20-30 years ago we were still PL 4, the Industrial Age. Items of 1 PL higher are available at +5 to the Purchase DC, being prototypes (and that is the limit for cutting edge technology).
Additionally, (crappy) mecha, robots, and cybernetics are available at PL 5. The cybernetics are limited to limb and organ replacements, though enhancements are available at PL 6.
I wouldn't be surprised if mecha were fairly common. Even the relatively crappy ones available at PL 5 allow a soldier to stand a good chance fighting against the more powerful exemplars.
Let's see...
Demonslayer (PL 5)
The Demonslayer works as a heavy assault mecha, typically used against the more powerful exemplars. It is less a vehicle, and more a large suit of power armor in design, though the increased bulk as a result of the armor and weapons is still enough for a human wearing it to count as Large.
A Demonslayer equipped with the standard equipment package (see below) has a Purchase DC of 37.
Size: Large
Superstructure: Alumisteel
Armor: Alumisteel
Armor Penalty: -6
Strength Bonus: +8
Speed: 25 ft.
Bonus Hit Points: 100
Hardness: 10
Bonus to Defense: +9
Reach: 10 ft.
Dexterity Penalty: -
Base Purchase DC: 36
Standard equipment package:
Pilot cockpit (torso and back), M-9 Barrage Chaingun (right arm), 6 50-round ammo belts for M-9 Barrage chaingun (boots), Bastion Tactical Sheild (left arm), M-55 Crud Rocket Launcher (shoulders), Comm system (no slots), Life Support System (helmet), Warpath Recoilless Rifle (handheld), Thunderbolt Shock Rod (handheld).
Often the pilot of the mecha is equipped with a mesh vest (which might or might not be Mastercraft), grenades, and additional ammunition for the Warpath Recoilless Rifle. These are not included in the mecha, and must be purchased seperately.