Combolands Secret Guilds: Rogues & Arcane

Rogues

  1. Take the Spymaster's request. Complete the Spymaster's council request — collect 75 gold during a single milestone. The request pays out a Spymaster vote, and using that vote adds Rogues to your current run and every run after it.
  2. Run Commercial to make the gold, Martial to re-fire it. The guide that documented this unlock recommends exactly that pairing: Commercial supplies buildings that grant gold, Martial supplies ways to trigger them again after placement. It singles out the Ballista and the Gold Pan as the two pieces most likely to get your first real pile of gold together.
  3. Use the Merchant councillor's arithmetic. With the Merchant in your council, buying a vote costs 3 while the vote gives 5. Repeating that is the cheapest documented way to clear a 75-gold target inside one milestone.
  4. Spend the vote. Using the Spymaster vote adds Rogues to your current run and to every run afterwards.

What you get: Buildings that trigger other buildings and collect money, usually carrying a minor drawback. In endless runs the Rogue Hideouts are what players credit for runaway xmult. Cannot be picked at the start of a run. The guide author who documented the unlock calls it "the most powerful guild in this game".

Source: Steam guide 'Guide: Unlocking Rogues & Arcane'; endless-mode thread

Arcane

  1. Find the Jewellery Box. It can turn up in the shop or in heirloom chests — the guide's phrasing is "basically everywhere". The reliable route is the Antiquarian councillor, which can both hand you the box and keep supplying gems if you keep feeding it votes.
  2. Collect 8 gems. They do not have to be unique, so duplicates count.
  3. Sell the completed box. That gives you the Lost Crown heirloom.
  4. Sell the Lost Crown. That gives a Wizard vote, and using the Wizard vote unlocks Arcane.

What you get: Buildings with unusual effects — strong, but by the same guide's reckoning not as strong as Rogues. Also not pickable at the start of a run. The Antiquarian councillor is the fastest route: keep feeding it votes and it can both hand you the box and keep supplying gems.

Source: Steam guide 'Guide: Unlocking Rogues & Arcane'

Two things that will make you think it failed

Unlock steps re-checked: