Making an extra-planar portal: how?

[qwertyu63]

I have a desire to build portals between planes. What ways are there that I can use? Thank you in advance.

[MonochromeTiger]

I have a desire to build portals between planes. What ways are there that I can use? Thank you in advance.

depends on context, are you using your own game? if so then you can easily just DM-logic some into existence. if not then sustained portals would likely require at least some magic items if not some epic/mythic spell casting.

[OldTrees1]

Presumably it starts with a Cleric casting Greater Consumptive Field (Extended by Metamagic Rod) near a bag of rats (or other animals with 9hp or less). Near the end of the Field's duration (when all of the animals are dead) the Cleric casts Gate (Extended by Metamagic Rod). Result: Extraplanar portal with a duration of 2 rounds per caster level (caster level = YES)

It takes a cl of 7200 (24hrs * 60min/hr * 10rds/min 1cl/2rds) to have it last 1 day with 1 casting.

If you have 5 17th level clerics each with 2 9th level spell slots it takes
7030 (7200-17 base cl * 5 clerics * 2 castings/cleric) animals per day.

[MonochromeTiger]

Presumably it starts with a Cleric casting Greater Consumptive Field (Extended by Metamagic Rod) near a bag of rats (or other animals with 9hp or less). Near the end of the Field's duration (when all of the animals are dead) the Cleric casts Gate (Extended by Metamagic Rod). Result: Extraplanar portal with a duration of 2 rounds per caster level (caster level = YES)

did you carry the convoluted or should we do the math a bit more?

[OldTrees1]

did you carry the convoluted or should we do the math a bit more?

I edited in more math for you :P

In seriousness you gave the DM answer and I gave my best attempt at a non epic PC version.

[otakumick]

The Forgotten Realms Campaign Setting has rules for Portals starting on page 59. Also in the book is the Create Portal Feat

[MonochromeTiger]

I edited in more math for you :P

In seriousness you gave the DM answer and I gave my best attempt at a non epic PC version.

I'll be honest, after reading the edit I laughed way more than I should have :P

[Mnemnosyne]

Gate doesn't work. It's instantaneous with an ability to control the summoned creature for 1 round/level for the calling creatures function, but it's Concentration (max 1 round/level) for the planar portal function. Unless your caster is going to sit there and concentrate forever.

[OldTrees1]

@Mnemnosyne
1 288 minute (4.8 hour) shift/day of concentration each is rather high.

However that was before I knew about the FRCS pg59 Portal rules [150K gp for a 2way portal]