Dedicated Caster of Pain

[GutterFace]

Not looking for cheese or shenanigans. but based on peoples experience in early to mid levels (face it no group i've played with 20 years of D&D ever went from 1 to 20)

what would be the most robust adventuring caster.

a Light Domain Cleric or a Dragon Origin Sorcerer?

does medium armor and a shield outweigh Sorcery points?

assume my Dragon heritage is a Red dragon.

[Falcon X]

I've never played a Cleric, but the Red Dragon Sorcerer is tough stuff. It gets +1 HP/lvl, boosts to fire spells, including it's fire cantrip, and can maintain a defensive spell if necessary.

I have one in the game I'm DMing right now, and she's our most valuable character (notably, she's the most strategy-minded too, so that helps...)

[asorel]

Not looking for cheese or shenanigans. but based on peoples experience in early to mid levels (face it no group i've played with 20 years of D&D ever went from 1 to 20)

what would be the most robust adventuring caster.

a Light Domain Cleric or a Dragon Origin Sorcerer?

does medium armor and a shield outweigh Sorcery points?

assume my Dragon heritage is a Red dragon.

My personal preference is Sorcerer if you want maximum combat viability. I haven't looked as much at the Cleric spell list, but, in addition to high-power blasting spells such as Scorching Ray, you get debuff spells such as Blindness/Deafness, and defensive spells such as (Greater) Invisibility, Mirror Image, and Haste, some of which only get better with Twinned Spell metamagic.

[Yagyujubei]

cleric doesnt have as much in the way of nuking like sorc does, but it still has some great spells like spirit guardians that can do sustained damage while they smash away in melee.

all in all though I'd say cleric is more survivable and has more utility, so in a party with any other characters who can bring the pain I'd rather have a cleric over a sorc.

[SharkForce]

if your DM will allow the unofficial favoured soul from the article about modifying classes, you could always just take both...

[XmonkTad]

The happy medium between Divine Caster Cleric and Charismatic Sorcerer is Paladin. But that really restricts you to melee and a lot of your spells are basically buffs for your melee attacks.

If you want spells to be your damage source you should keep in mind that spell damage is almost always inferior single target damage compared to melee weapon damage. In that vein, a fire sorc is probably the best for doing damage overall. There are tons of fire spells, but fire resistance/immunity is so very common that you really want to take Elemental Adept (fire). If you're starting below level 4, it's almost worth being a variant human just to get that feat.

[Rhaegar14]

I've seen two people call out the Sorcerer as having better blasting spells, so I'd like to point out that Light Cleric gets Burning Hands, Flaming Sphere, Scorching Ray, Fireball, and Wall of Fire as domain spells, though a Red Dragon Sorcerer would do more damage with those spells between the Charisma bonus and metamagic. As for utility, the simple fact that the Cleric is a prepared caster with rituals likely more than makes up for any superiority of the Sorcerer's spell list. It is a tough call and there are pros and cons to each, but I wouldn't immediately dismiss Cleric. I think which fluff you enjoy is really the best way to decide it.

[asorel]

I've seen two people call out the Sorcerer as having better blasting spells, so I'd like to point out that Light Cleric gets Burning Hands, Flaming Sphere, Scorching Ray, Fireball, and Wall of Fire as domain spells, though a Red Dragon Sorcerer would do more damage with those spells between the Charisma bonus and metamagic. As for utility, the simple fact that the Cleric is a prepared caster with rituals likely more than makes up for any superiority of the Sorcerer's spell list. It is a tough call and there are pros and cons to each, but I wouldn't immediately dismiss Cleric. I think which fluff you enjoy is really the best way to decide it.

I don't believe the utility capabilities of the Cleric were ever called into question. However, as OP was concerned with creating a blaster character, the Sorcerer's limited spell list wasn't called into account.

[Rhaegar14]

My personal preference is Sorcerer if you want maximum combat viability. I haven't looked as much at the Cleric spell list, but, in addition to high-power blasting spells such as Scorching Ray, you get debuff spells such as Blindness/Deafness, and defensive spells such as (Greater) Invisibility, Mirror Image, and Haste, some of which only get better with Twinned Spell metamagic.

My fault for misreading/using a looser definition. I generally think of most spells that don't directly deal damage as utility to some extent.

[GWJ_DanyBoy]

As to which is tougher/ more robust, it seems like a toss up. Light Cleric can walk around with 19 AC no problem with half-plate and a shield. Dragon Sorc gets free mage armor, so up to 18 AC if they max DEX (No comment on how likely this is). Cleric has buff spells and heals, Sorc has extra HP and their own defensive/enhancing spells like Shield, Blur and Counterspell.

[asorel]

As to which is tougher/ more robust, it seems like a toss up. Light Cleric can walk around with 19 AC no problem with half-plate and a shield. Dragon Sorc gets free mage armor, so up to 18 AC if they max DEX (No comment on how likely this is). Cleric has buff spells and heals, Sorc has extra HP and their own defensive/enhancing spells like Shield, Blur and Counterspell.

Regarding defense, Sorcerers get proficiency in CON saving throws. Ideally, a squishy caster shouldn't get hit at all, but CON proficiency is excellent for maintaining Concentration spells. This becomes more important once one considers that one of the Sorcerer's biggest advantages is keeping two copies of a Concentration spell up at the same time with Twinned Spell.

[Rhaegar14]

As to which is tougher/ more robust, it seems like a toss up. Light Cleric can walk around with 19 AC no problem with half-plate and a shield. Dragon Sorc gets free mage armor, so up to 18 AC if they max DEX (No comment on how likely this is). Cleric has buff spells and heals, Sorc has extra HP and their own defensive/enhancing spells like Shield, Blur and Counterspell.

I think it's pretty fair to assume that a blaster Sorc is not gonna max their Dexterity (I know you said no comment on likelihood, but the likelihood is an important part of the comparison). The Cleric has the clear edge in AC. HP is a moot point, as the Cleric's larger hit die cancels out the Dragon Sorcerer's +1 hit point/level. The Sorcerer definitely does have the edge in personal defense spells though.

@asorel: True, but a Cleric is likely to pick up Resilient: Constitution for exactly that reason at some point anyway, and their higher AC makes it less likely that ranged attackers can hit them to force a Concentration check. Constitution proficiency is a big point in the Sorcerer's favor if feats are off the table, however.

[GWJ_DanyBoy]

Sorc has extra HP

Correction: They have the same HP, as the Sorc's hit die is normally a d6, and clerics have a d8.

[RulesJD]

Sorc 1
Warlock 2/3 (Pact of Tome + Fiend) Invocations to add Cha damage + rituals. Short rest = 4 sorc points regained due to Warlock slots
Sorc up to at least 6 (add Cha to fire damage)
After that, you can go Warlock 5 to get another invocation (Devil's Sight for Darkness combo to generate advantage) or just keep going Sorc. You get proficiency in Con saves, the best at-will caster damage (Hex + Eldritch blast), the best caster Nova damage (Quicken Scorching Ray + Eldritch Blast all adding Cha per hit + Hex on each hit), but all the utility of the ritual spells (Find Familiar, Detect Magic).

You have utility (self-heal, ritual spells), amazing damage (Meta-magic + Elritch Blast + Hex + Cha to almost all damage), and great survivability (at least 16 AC + Shield + Absorb Elements + built in fire resist).

I also advocate for Vengeance Paladin + Warlock. Gain Ritual spells (utility + Hex for grappling/shoving prone) + suuuuuper tanky (Cha to saves, plate, etc) + suuuuper damage at any range (Eldritch Blast + Hex) + healing (Lay on hands + Cure wounds on short rest rechargable + Fiend self-heal) + pure fun (Darkness + Devil's Sight). It takes up to level 9 to really come online but even before that it offers tremendous versatility with pure caster power.

[asorel]

I think it's pretty fair to assume that a blaster Sorc is not gonna max their Dexterity (I know you said no comment on likelihood, but the likelihood is an important part of the comparison). The Cleric has the clear edge in AC. HP is a moot point, as the Cleric's larger hit die cancels out the Dragon Sorcerer's +1 hit point/level. The Sorcerer definitely does have the edge in personal defense spells though.

@asorel: True, but a Cleric is likely to pick up Resilient: Constitution for exactly that reason at some point anyway, and their higher AC makes it less likely that ranged attackers can hit them to force a Concentration check. Constitution proficiency is a big point in the Sorcerer's favor if feats are off the table, however.

Cleric definitely has the edge in AC, no argument there. I'd still count CON proficiency as a favorable point for Sorcerers even with Feats, as every Feat invested is a delay in upgrading your primary casting stat.

Personally, I would give Clerics the edge in defense. Although making CON saves to maintain concentration is technically a defensive actions, it's arguable more in line with offensive capability, as your primary use for this ability is to maintain offensive spells. The notion of Clerics being more defensive and Sorcerers more offensive is corroborated further by assuming Sorcerers will likely take Elemental Adept (Fire) as feat, in the same way that Clerics are likely to choose Resilience (CON).