I want balanced and upgradable powers

[Quickleaf]

For sure the DM can always ad-lib whatever they want to add realism, kudos on you for running it that way. But from my admittedly non-extensive 4e experience (I've played about 6 sessions, including at Gen Con, and I own the core books), the powers are intended to do no more or less than what's described in the power text (usually x dice damage + some effect that lasts 1 round and poofs out).

From what I can tell, 4ePHB p.276, 'Type' of damage like Fire does not RAW imply setting things afire or generating heat. Pls correct me if wrong.

Actually 4e RAW puts it entirely in the hands of the DM. The relevant quotes...

PHB 57 Target
At the DM’s discretion, a power that targets a creature can also target an object, whether or not the power identifies an object as a potential target.

PHB 2 Glossary
Attacking Objects: With your DM’s permission, you can use a power that normally attacks creatures to attack objects. See the Dungeon Master’s Guide, page 65, for how to damage objects.

 

[Neonchameleon]

For sure the DM can always ad-lib whatever they want to add realism, kudos on you for running it that way. But from my admittedly non-extensive 4e experience (I've played about 6 sessions, including at Gen Con, and I own the core books), the powers are intended to do no more or less than what's described in the power text (usually x dice damage + some effect that lasts 1 round and poofs out).

From what I can tell, 4ePHB p.276, 'Type' of damage like Fire does not RAW imply setting things afire or generating heat. Pls correct me if wrong.

Type of damage fire = heat based damage in just about everything. On the other hand it is normally sudden and rapid. It's a shock rather than a burn - and doesn't provide time for things to catch on fire. I don't expect it to catch anything an adventurer carries on fire - they take precautions if they have any brains at all. On the other hand use AoE fire powers in a library or near oil barrels and there's all sorts of trouble - this is normally listed in the scenario (if well written) by the things that are flammable. Fire damage only catches people on fire if it's something like ongoing fire damage.

And RAW Basic D&D I believe worked the same way.

 

[Styracosaurus]

This is similar to 3rd edition metamagic feats that allowed a higher level spell slot to be sacrificed to add effect to a lower level spell.

I like the idea of a a mage being focussed on a certain type of spell type/ flavor rather than having a group of unrelated spells.

Fire, cold, force, lightning etc...... You can have rays, blasts and walls.

You could still have generalists but right now it is difficult to have a magic user that has a theme.

 

[Firzair]

This is similar to 3rd edition metamagic feats that allowed a higher level spell slot to be sacrificed to add effect to a lower level spell.

I like the idea of a a mage being focussed on a certain type of spell type/ flavor rather than having a group of unrelated spells.

Fire, cold, force, lightning etc...... You can have rays, blasts and walls.

You could still have generalists but right now it is difficult to have a magic user that has a theme.

Yeah, the idea is based upon 3e metamagic.
In fact I don't like 4e at-will/encounter/daily power division... for 5e I'd like to see balanced classes with different mechanics and their powers should be comparable.

I don't know where the idea of some posters came from, that a fireball in this idea couldn't be used to set things on fire... there's nothing ruled against that...
The wording of the power is the fluff, the effects are defined.
In general all fire effects should be able to set things on fire, but perhaps the probability should be based upon damage and duration. A short burst of a flame that does 1d4 fire damage is unlikely to light things afire, a stream of fire that deals 4d6 fire damage per round is something completely different, especially if the streams hits you for consecutive rounds.

I'd like to have effects described by what's the basic effect is and their possible progressions, the you can design powers/spells/feats from there, just wording the fluff.
An effect that deals 1d6 weapon damage to 5 targets at medium range could be a "Hail of arrows" for the ranger or the "Stone shower" as a spell for an earth based sorcerer. But just by looking at the effect(s) the DM can decide at what level this power can be gained. And from there on, the player can improve the powers in defined ways. The ranger could inrease the number of targets or the reange or the damage die to 1d8 when he gains a level.

Imagine a player that has an idea for a strange new power of his character that he wants to learn. He tells the DM the wording of the power, the DM looks at the effects and thus the power could be defined or the DM suggests a pre-version of the power that is appropriate for the level of the character but that can be improved to someday exactly match the power the player wanted.

And no other player should complain that this new gadget is overpowered... dream...

 

[Tallifer]

They could simply have a "Fireball" spell and a "Super Fireball" spell at a higher level and a "Super Mega Fireball" at an even higher level.

That is just filling pages pointlessly. If the Fireball scales (like it did in AD&D), no need to write another spell block for each higher level.

That was one of things I HATED most about Rolemaster. I would buy a book of spells thinking, "Wow. 200 pages of spells!" But then I would look at them and most of them were just the same spell a hundred times for different levels and different types of elemental damage.

 

[MichaelSomething]

That is just filling pages pointlessly. If the Fireball scales (like it did in AD&D), no need to write another spell block for each higher level.

That was one of things I HATED most about Rolemaster. I would buy a book of spells thinking, "Wow. 200 pages of spells!" But then I would look at them and most of them were just the same spell a hundred times for different levels and different types of elemental damage.

Then Mutants and Mastermind is the system for you! You can pick a generic blast power and say call it fireball/ice blast/ninja star throwing/whatever.

If you want abilities to scale and have it work in a system, you can do it, but D&D doesn't really focus on that. 5E is said to have flatter math, making scaling easier to houserule in.