Advanced Soul Ops Boss Rush Guide: Wave order from start to finish
About
OverviewAdvanced Soul Ops Boss Rush is an Undertale-themed Roblox game where you fight a lineup of bosses one after another, earn coins, upgrade your tier, and unlock stronger characters. This guide covers the wave order, how rare bosses appear, and what to do when you are just starting out.
What is on this page
Contents
Wave order from start to finish
Step
Every run starts at Wave 1 and works upward in a set sequence.
- Wave 1 Classic Sans is your first target and the gateway to everything that follows.
- Wave 2 Fell Sans comes next, followed by Outer Sans at Wave 3.
- Wave 4 Swap Sans, then Killer Sans at Wave 5 and Dust Sans at Wave 6.
- Wave 8 Horror Sans and Murder Time Trio both sit here; Nightmare Sans follows at Wave 9.
- Wave 10 Chicken Insanity Sans, then The Puppets at Wave 11, Error Sans at Wave 12, and Ink Sans at Wave 13.
Rare bosses and how to trigger them
Check
Some bosses sit outside the normal wave order entirely. Each has its own trigger — either a probability roll after a certain wave or an action you have to take during the run.
- Hard Mode Sans has a 1-in-4 chance of appearing after you beat Classic Sans.
- Fell Phase 2 has a 1-in-5 chance of appearing after you beat Fell Sans.
- True Dust Sans has a 1-in-10 chance of appearing after you beat Killer Sans.
- Insanity Sans has a 1-in-8 chance of appearing after you beat Horror Sans.
- Assured Prey (Wave 7) only appears if you eat the hotdog before facing Horror Sans.
- Final Insanity Sans requires you to find his sword (1-in-5 chance of spawning) and then kill Chicken Insanity Sans in that order.
- Avenge Sans has a 1-in-7 chance of appearing after Chicken Insanity Sans.
Getting started
Summary
Your immediate goal is to beat Classic Sans, collect the coins that drop, and put those coins toward upgrading your tier.
- First goal defeat Classic Sans at Wave 1 to open the rest of the wave lineup.
- Coins every boss you beat drops coins; spend them on tier upgrades.
- Stronger characters higher tiers unlock better characters.
- Room size up to six players can share one room.
Glossary
Glossary- Wave
- A single numbered boss fight in the run; you clear them in order from Wave 1 upward.
- Tier
- A level of character strength that you raise by spending the coins you earn from beating bosses.
- Rare boss
- A boss that appears only when a probability condition is met or a specific in-game action is completed, separate from the normal wave order.
- Boss Rush
- The format of this game — multiple bosses fought back to back in a single continuous run.
Common questions
FAQHow do I get a rare boss to appear?
It depends on the boss. Most rare bosses have a random chance of spawning after you clear a specific wave — for example, True Dust Sans has a 1-in-10 chance after Killer Sans. Assured Prey is different: you must eat the hotdog before Wave 7 or the fight never triggers.
Can I play with friends?
Yes. A single room holds up to six players at the same time.
What is the 404-NOT-FOUND badge?
The official description says only "An Error has occurred. Please wait till further notice. (Error Code: 404)" and does not state how to obtain it.
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