Siege Mode: Surviving Past Wave 25
Ten strategies for pushing deep into Hard Siege Mode, ordered the way a run actually plays out. Covers the blessing terminal, which atonements to reroll, the Tech Priest credit economy, Tarantula sentry placement, the wave timer, and the squad composition that carries all of it.
Before you start
- Siege Mode unlocked. It runs on its own economy and progression, separate from Operations
- A class levelled far enough to have its team perks available. Several tips depend on them
- A full squad of three. Bots will not spread across the buy terminals to keep Tech Priests up
Builds that make this easier
At Every Sector Start
Never run past the blessing terminal
Every time you begin a run or finish a sector, the game hands you a free power increase at the blessing terminal. Skipping it is the single most common mistake in random squads. Blessings are not minor stat bumps, they change how strong the character feels for the rest of the run, and the gap compounds as waves scale. Enemies scale whether or not you took one, so refusing the stop is choosing to fall behind. It costs a few seconds.
Look immediately left off the elevator
The blessing terminal sits to your left as soon as you step off the elevator platform. Knowing where it is stops it from being missed in the rush to push forward.
Pick blessings that match your loadout, not the best one on the board
The question to ask is not which blessing is strongest, it is which blessing is strongest for the class, perks, and weapons you are already running. On a precision weapon like the Las Fusil or a bolt sniper, blessings that pay out on headshot kills and precision damage amplify what you are already doing. On a Vanguard running Unmatched Seal with Adrenaline Rush, you are already drowning in survivability, so another healing blessing is close to wasted and extra damage or cooldown reduction does more. Stacking into one direction is what makes a character feel dramatically stronger.
Reroll the three atonements that kill runs
Friendly Fire, Stick Together, and Stay Apart are the three worth spending on. Friendly Fire is the worst of them. Once waves get busy, teammates roll through your line constantly and explosives are going off everywhere, so downing a battle brother by accident stops being a question of care. Stick Together and Stay Apart both fight your positioning, and how badly depends on the squad and the objectives you draw.
Reroll from the top left of the same terminal for 250 credits
The reroll option sits in the top left corner of the blessing terminal. Do not chain rerolls hunting for a perfect result, because 250 a pull drains an early economy fast. One or two to escape a run-wrecking atonement is insurance worth buying.
Read your atonement before the doors shut
Once you leave the elevator platform and the doors close behind you, they stay closed for that sector. Check the atonement on screen and settle it while you can still reach the terminal.
Run the Credit Economy
Buy Tech Priests instead of banking credits for later
Hoarding credits for the late waves was correct before the Siege Mode overhaul and is not correct now. Tech Priests generate credits the whole time they are alive, so buying early is what funds everything else. The snowball is the point.
Split the squad so every buy terminal has one
Each battle brother should buy a Tech Priest at a different terminal rather than everyone crowding one. Call it out, take a terminal each, and replace them the moment they go down.
Stop around wave 15 to 20 on Hard
On Hard the cutoff is roughly wave 15 to 20, and on Normal closer to wave 25 to 30. Past that the enemies hit hard enough that a Tech Priest usually dies before it earns back what it cost. You can still buy them later, the test is just whether this one will live long enough to pay for itself.
Buy the Tarantula Sentry Gun upgrade off the rip
This is a one-time purchase that doubles every Tarantula Sentry Gun you buy afterward, giving you two per purchase instead of one. It carries across every sector and every buy terminal for the rest of the run, which makes buying it early strictly better than buying it late. It also protects your Tech Priests while the squad is away on objectives, so the two purchases feed each other.
Prioritise small ammo boxes over large caches
Small boxes are more credit-efficient, and they are far faster to use. Late Siege is chaotic, and holding an interact button for a couple of seconds on a large cache while enemies close in is how you get downed. A small box is a single press on the way past.
Only the small boxes refill special ammunition
This is the real reason to prefer them. Large caches do not replenish special ammunition, small boxes do. On something like the Heroic Deathwatch Heavy Bolt Rifle with the grenade launcher attachment, those grenade rounds are a large share of your damage, and only the small boxes bring them back.
Hold the Map
Tarantula sentries have replaced the triple heavy bot plan
The triple heavy bot strategy was the pre-overhaul answer and still works, but sentries are the better investment now. They deal damage continuously, thin waves before they reach you, hold objectives, and take pressure off the squad without anyone babysitting them.
Start buying them around wave 5 on Hard
Wave 5 on Hard and around wave 15 on Normal is where they start earning their cost, which is usually the same point your Tech Priests begin needing protection. Treat those as starting points rather than rules and shift them for how strong the squad is. From there, aim to have sentries active every wave. They also close runs out faster.
Spread them across the map instead of stacking one lane
Place sentries near spawn points and spawn roots, but do not commit everything to one approach. Enemies do not always come from the same direction, and the fight drifts as your squad rotates for objectives or falls back to recover. Coverage spread around the map means you still have support wherever the fight ends up. Funding this is exactly why the Tech Priest economy matters.
Skip mini objectives that put a body at riskOptional
With a healthy Tech Priest economy, the credits from mini objectives stop being worth much. The battery cell objective is the clearest example. Whoever carries it loses mobility and most of their combat options, and the rest of the squad has to peel off and protect them, which drags everyone out of position. Weigh that against what it pays. Staying alive and keeping Tech Priests up beats clearing every marker on the map.
Clear the wave before the timer enrages it
The overhaul added a wave timer, and running long enrages the enemies. Enraged enemies hit harder and gain a large amount of health, which is where the bullet sponge complaint about late Siege comes from. Everything drags at that point, you burn far more ammo and resources, and the squad takes more chances to get overwhelmed. Blessings, clean atonements, Tech Priests, and sentries all exist to make waves die faster than the timer.
Squad Composition
Every class works, but two are close to mandatory
This is the creator's opinion rather than a hard requirement, and every class is viable in Siege. Two of them bring team-wide utility that nothing else replaces.
Tactical, for Auspex Scan and Secure Stockpile
Auspex Scan is one of the strongest abilities in the game and it is what lets a squad melt bosses and elites during boss waves. Secure Stockpile is the other half, replenishing melta bombs, krak grenades, shock grenades, the pyre blaster grenade, and the rest of your equipment across a run.
Vanguard, for Unmatched Seal
Unmatched Seal is arguably the strongest team perk in the game. It heals the squad off kills on Extremis-level and higher enemies, and Siege throws plenty of those at you even on Normal, so it adds up quickly. Blessings cannot be relied on to cover this, since Leman Russ is not guaranteed to show up in a given run. Without a reliable healing source you end up spending credits on medkits, which is credit you would rather put into the economy.
Third slot is open, with Heavy the strong defaultOptional
The last slot is genuinely free. Heavy is the recommendation for raw damage, and the weapon barely matters between the Heavy Bolt Rifle, Heavy Bolter, Heavy Plasma Incinerator, Multi-melta, and Pyre Cannon. The real draw is Bonds of Brotherhood, which revives teammates at full health. It does not clear the mortal wound, but it drops the cost of clearing one from two or three medkits to a single medkit. Mortal wounds always have to be cleared in Siege, so that saving repeats all run.