Hey there! Anyone remember the days of weird/hilarious optimization challenges? If you don't, here's how it works:
1. Make a lvl20 character
2. Make that character take 5 different multiclasses
3. ???
4.Profit!
5. Share with others, try out different combos for different effects; All CHA, No Spellcasting, Monk-Paladin (a difficult combo), etc. Let your imagination run wild!
6. Silver Star for not using Warlock, it's an incredibly powerful dip class, and most every multi can make use of it.
7. Silver Star for keeping 5 Ability Score Increases/Feats
8. Gold Star for Both!
Note that I won't be able to maintain the thread. I've got too much going on my plate at the moment, so I can't link all the different builds in a nice lovely list. 
That said, let 'em rip and let's see what we can come up with!
I'll go first!, just a Bronze Star build, but powerful and interesting...
Pallassassin! - Half-Elf
Stats after Racial boosts, Standard point buy-
13 Str / 16 Dex / 14 Con / 8 Int / 8 Wis / 16 Cha
Fighter (Battle Master) 4/ Warlock (Fiend) 2/ Paladin (Vengence) 6/ Rogue (Assassin) 4/ Bard (Lore) 4
First level Paladin, for armor and WIS proficiency. All ASI's go to DEX and CHA. Use a Rapier and Breastplate/Studded Leather
Here's how you abuse several class features at once! Smite, Divine Protection, Full Powered Eldritch Blast, Darkness + Devils Sight, +8 Initiative and Assassinate, 2d6 Sneak Attack, Expertise in 4 Skills, Proficiency in 8 Skills, Action Surge, Manuvers, and a full 20 DEX and CHA! A powerful and versitale damage-dealer, social specialist, and party scout. Warlock adds a hell of alot for just 2 levels, you get the powerful and effective Darkness + Devils Sight, and a poweful direct damage dealing Eldritch Blast when you can't get the drop on Team Monster. Also, no Feats, if that's your sort of thing!
Ooh, this sounds fun. Let's aim for a gold, and while I'm at it, try to hit as many proficiencies as possible.
I'm taking it literally when you say five ability score increases, instead of assuming you meant "no feats". The requirement for five Ability Score Increases is interesting, since it prevents a lot of 3-level dipping and favors Fighter.
Here's my suggestion, which goes for broke on skill checks, archery, and a couple other oddball tricks.
Standard human (since the variant gives a feat). The backgrounds are all largely the same for this, so pick to taste.
Rogue (Assassin) 4 / Fighter (Eldritch Knight) 6 / Bard (Lore) 4 / Cleric (Knowledge) 2 / Ranger (Hunter) 4
(Note: The class order can be juggled more or less as you see fit.)
Using 27 point-buy, 8 Str, 15 Dex, 13 Con, 11 Int, 13 Wis, 13 Cha before racial modifiers.
This class structure has five ability score increases, meaning we finish with 9 Str, 20 Dex, 14 Con, 12 Int, 14 Wis, 20 Cha.
Choices along the way:
Expertise: Stealth, Perception, Persuasion, Deception
Fighting Styles: Archery, Dueling
Blessings of Knowledge: Arcana, History
Favored Enemy: Monstrosities (or to taste)
Favored Terrain: Forest (or to taste)
Hunter's Prey: Colossus Slayer
Attacks:
Initiative +8, thanks to Jack of All Trades.
Ranged: Two attacks at +13 (1d8+5 piercing; +2d6 Sneak Attack +1d8 Colossus Slayer) with a normal longbow, not using any buff effects.
A rapier is pretty close to this as backup melee, at +11 / 1d8+7.
Skills:
Proficient in 13 skills (double proficiency in six), capable of getting any of the remaining 5 skills on demand via Channel Divinity (and half proficiency in all of them without that).
Tools: Thieves' tools, one musical instrument, one type of artisan's tools, plus whatever's listed in the background. Channel Divinity can pick up proficiency in any other tool you want (though you already get half proficiency with ability checks with them.)
Defenses:
AC: 18 with Mage Armor.
HP: 149 taking the average every time. (Second Wind: 1d10+6)
Saves: Dex +11, Cha +11. (This is one area that will suck if feats aren't in play.)
Spellcasting: 4/3/3/3/2/1 spell slots. Bard DC 19 / attack +11. EK DC 15 / +7. Cleric/Ranger DC 16 / +8; 4 cleric spells prepared.
Cantrips: Three bard, three cleric, two wizard. (The exact choices don't matter, you'll practically never use them.)
Bard spells known: Faerie Fire, Charm Person, Dissonant Whispers, Heroism, Detect Magic, Invisibility, Suggestion
EK spells known: Shield, Protection from Evil and Good, Expeditious Retreat, Mage Armor
Cleric spells prepared: Cure Wounds, Silence, Guiding Bolt, Bless, Identify (domain), Command (domain)
Ranger spells known: Hunter's Mark, Ensnaring Strike, Hail of Thorns, Longstrider
(That should be a decent selection of advantage, disadvantage, support, defense, and countermagic. Not as ideal as I'd like re: concentration or reaction spells, but servicable.)
TL;DR: Your restrictions are so restrictive, the only way they could be more restrictive is if you restricted us to specific builds.
.
That all said, I win:
Fire Dragon Sorcerer 6/Fighter 6/Bard 4/Wizard 4:
Start with a 16 Cha. Boost Cha. Spam Scorching Ray. Action Surge for more nova. Bard adds Cutting Words, Jack of All Trades and Inspiration Dice. Wizard adds ritual casting and Divination Portent.
Bard or Wizard can be swapped for Rogue to pick up Assassinate for even more nova.
Feat wise; Elemental something, to ignore fire resistance, and Magic Initiate, for Hex and Eldritch Blast.
EDIT: Or you can ignore that because it's four classes. Okay, same as above, but Sorcerer 8/Fighter 6/Wizard 2/Bard 2/(Warlock/Cleric) 2.
Edit 2: That's only 4 abi. Yeah too restrictive. Just reduce two of the level 2 classes to level 1 and bumb Fighter to 8.
Oh look, Fighter again. You've the spell slots of a level 10 caster, use them to smite. Mage Hand can grant advantage. Divination Portent is still just as good, as is Jack of all Trades.
But yeah, this just boils down to Fighter 8+2 lvl 4 classes+2 classes from the level dip guide.
FabulousRex wrote:
OP is not maintaining the thread.
Use 5 or more classes. Fixed.
Miladoon wrote:
Tempest_Stormwind wrote:
Ah, I too was tired when I wrote the first one! I'm not trying to say these are hard and fast rules, just an academic excersise. The build I posted was a short one, but was only Bronze. Try thinking about the most powerful Bronze build, where you can do anything you please. It's tiered so that people can choose which level suits them. Perhaps a simple renaming:
No Restrictions- Just make a dude with 5 classes and see what kinda craziness you can pull off!
5 ASIs or Feats- A clarification, sorry for tired writing. And this option is to simulate what a 'normal' character has for increases. Sure it favors Fighter, but perhaps you can divide it into Non Fighter builds as well.
No Warlock- I should probably drop this one. It's blatant class favoritism. But Warlock makes it impossible to do the next one...
Full Caster- Talked about it with my players, and this sounds like an especially interesting challenge! Just like it says on the tin, nothing but full casters the whole way. Considering that there's only 5 total so far, I look forward to that one. 
9th Level Slots- A toned-down version of above, also a sliding scale. How powerful can you be with 8th or 6th level spells? Generally the higher the more impressive, but an uber build with only lvl5 slots can also be impressive.
SAD- Single Attribute Dependent, just stick to a single attribute for all of your attacks and spellcasting, if any. WIS and CHA builds are especially interesting!
Just tag it with whatever applies, and we'll have competitions in categories.
Maybe if you modified the No Warlock to No Warlock or Fighter for a Silver Star. Because your original challenge was biased towards the Fighter and Against the Warlock.
I had a go and came up with Salistri the Unwary, Seer of Destiny, Lore Master and Guardian of Mysteries. Without using Wizard (Diviner). Although if I had used Diviner then it would probably replace Paladin.
Rogue (Arcane Trickster) 4, Bard (Lore) 4, Sorcerer (Green Dragon) 4, Paladin (Devotion) 4, Cleric (Knowledge) 4
Salistri was a Lightfoot Halfling, to charismatic for his own good, whose preferred trick as a Charlatan, was to tell fortunes to the gullible, usually revealing that something bad will happen in the not to distant future, which can be averted if they purchase an enchanted candle or magic amulet or token from him.
He gains Expertise in Deception and Insight. Some bardic training provides further expertise in Sleight of Hand and Thieves Tools. His latent sorcery is awoken ( Great Grandmother dealt with a Green Dragon, she was a powerful Sorceress). Guided by fate Salistri was bound to serve Knowledge, after receiving a vision he was anointed as a Paladin of Gnosis (Knowledge), further along he realises that he is a priest to the Gods of Knowledge. All in all the charming Trickster, who cheated folk becomes bound to true knowledge and truth.
Stat wise, Salistri has several options with ability score improvements being essential. 11 Arcane Cantrips, 4 Divine Cantrips,16 Spells known of 1st and 2nd Level, Multiclass Spellcaster Slots as a 15th Level. Yet only knows 1st and 2nd level spells. Yet have spell slots upto 8th. Rogue knows 4 (1st Level spells- 3 Illusion or Enchantments), Bard knows 7 spells (minimum of 3 1st level spells with a maximum of 3 2nd level spells), Sorcerer knows 5 spells (3 minimum 1st level and 2 maximum 2nd Level) also has Subtle and Quickness Meta Magic.
Salistri is also a skill monkey with 6 skill proficiencies at 1st level as a Rogue, gaining 1 skill proficiency as a Bard, then 3 skill proficiencies as a Lore Bard, and 2 skill proficiencies via Blessings of Knowledge at 17th level for a total of 12 skill proficiencies, 4 expertise, Jack of All Trades by default and Knowledge of the Ages from 18th level.
I might have a go at a total caster, a Natures Avenger, a total fighter and a Divine Inspired. Total Caster would be Bard, Cleric, Sorcerer, Warlock, Wizard (16th Level Multiclass Spellcaster with 4th Level Warlock Pact Slots. Natures Avenger would have Barbarian, Cleric (Nature), Druid, Paladin (Ancients) and Ranger. Divine Inspired would have Bard (Valor(Music is a divine gift as is inspiration)), Cleric (Light, Tempest, War or Healing), Druid (Moon), Paladin (Devotion), and Barbarian (Totem) or Monk (4 Elements). Martial Master- Barbarian (Berserker), Fighter (Battle Master), Monk (Open Hand or Shadow), Ranger (Hunter), Rogue (Assassin).
5 full casters, Agonizing Blast + Eldritch Blast for cantrip, Cutting Words, Hex + Any multi-attack, Scorching Ray for the 9th level slot challenge.
Oh and it runs entirely off of Cha for attacks, and can run entirely off of Cha given the range aspect (ignoring MC requirements).
spanglemaker wrote:
Idea wise, there's a strange convergence
among Skill monkey multi dips and
Cantrip monkey multi dips, that also gets
a near max Ritual book collection.
Warlock can add in that repeatability, too.
It would bore/annoy the snot out of partymates
to have 1 dude doing 99% of the between combat.
Hey guys, I'm sorry I'm so productive ...