Tactical Tuesdays: Clearing the Building
Entering the Crimson Tower
There are few places in action fiction more dangerous than a building full of enemies.
Whether it’s terrorists holding hostages, cultists summoning something best left unnamed, alien infiltrators nesting in a corporate headquarters, or a supervillain’s private army entrenched floor by floor, the task remains the same: get inside, move upward, complete the mission, and survive long enough to tell the tale.
Movies make it look simple. The hero kicks a door open, dives through a hail of bullets, and emerges victorious. Realistically, and in a good TTRPG, building clearance is one of the most terrifying operations imaginable. Every doorway hides uncertainty. Every office conceals danger. Every stairwell is a potential death trap.
That’s why today’s Tactical Tuesday is dedicated to one of the most iconic action scenarios ever conceived: clearing the building.
Why Buildings Favor the Defender
A defender knows the terrain.
The attacker does not.
That reality alone creates an enormous advantage. Defenders choose firing positions, prepare ambushes, barricade entrances, and establish fields of fire. Every room becomes a miniature fortress.
Attackers, meanwhile, must expose themselves repeatedly. Every hallway must be crossed. Every office must be searched. Every closed door presents a question that can only be answered by opening it.
The result is tension.
Good building-clearance scenarios should feel less like a battlefield and more like exploring a dungeon where every monster carries an assault rifle.
Room-by-Room Movement
One of the greatest mistakes GMs make is treating an office floor as one giant combat arena.
Professional clearing operations happen incrementally.
The team secures one area before moving to the next.
A typical progression looks like this:
- Secure the hallway.
- Clear adjacent rooms.
- Confirm no threats remain.
- Advance to the next area.
- Repeat.
This creates natural pacing.
Players begin making meaningful tactical choices:
- Do we split up?
- Who watches the rear?
- Do we check every office?
- Do we bypass unexplored rooms?
- Do we spend time searching for clues?
Every choice introduces risk.
A forgotten storage closet behind the team can become tomorrow’s ambush.
Why Doorways Are Dangerous
Doors are lies.
They appear harmless.
They’re not.
A closed door conceals information while simultaneously restricting movement. Whoever controls the far side sees the battlefield differently than those approaching it.
A defender behind cover can prepare:
- An ambush
- A crossfire
- A grenade trap
- A sniper position
- A hostage situation
The attackers know none of this.
The moment they cross the threshold, the situation reveals itself.
That’s why experienced operators treat every doorway as potentially lethal until proven otherwise.
As a GM, doors become tension generators.
The simple act of turning a doorknob should make the table nervous.
The Fatal Funnel
Among tactical professionals, there is a concept often called the Fatal Funnel.
The doorway.
When entering a room, everyone must pass through the same narrow opening.
This restricts movement and limits options.
Imagine defenders covering the entrance. Every attacker entering automatically passes through the defenders’ chosen kill zone.
In game terms, the doorway becomes a tactical chokepoint.
A smart defender may position:
- Heavy weapons
- Automatic gunfire
- Snipers
- Energy weapons
- Super-powered enforcers
Right where entering characters must appear.
When players understand the danger of the fatal funnel, they stop charging blindly through doors and start thinking tactically.
And that’s where the fun begins.
Stacking and Entry Techniques
Action heroes love solo assaults.
Teams survive through coordination.
Before entering an uncleared room, operators often form what’s called a stack.
Each member has a role:
Point
- First through the door.
- Immediate threat identification.
Second
- Covers opposite angles.
- Prevents blind spots.
Third
- Reinforces the strongest threat area.
Fourth
- Security and rear observation.
In RPG terms, stacking creates teamwork opportunities.
The sniper may cover the doorway.
The heavy hitter enters first.
The hacker prepares electronic intrusion.
The psychic scans for hidden minds.
The superhuman bricks the door open.
Each player contributes.
The objective isn’t realism for realism’s sake.
The objective is giving every character something exciting to do.
Combat Versus Hostage Situations
Hostages change everything.
A straightforward firefight becomes a balancing act.
Every shot carries consequences.
The situation may require:
- Negotiation
- Stealth
- Diversion
- Precision attacks
- Simultaneous breaches
The villain knows the heroes care about innocent lives.
That knowledge becomes a weapon.
A good hostage situation should force difficult choices.
Can the heroes afford patience?
Can they risk assault?
What happens if the hostage is not where the intelligence reports claimed?
The best rescue operations create tension before a single shot is fired.
Tactical Set Piece:
The Crimson Tower
“Ten stories. Hundreds of rooms. One chance.”
The Crimson Tower is a modern office structure now occupied by hostile forces.
The exact nature of the enemy can vary:
- Terrorists
- Criminal gangs
- Alien infiltrators
- Occult cultists
- Corporate mercenaries
- Supervillain operatives
The building itself becomes the adventure.
Floor One: The Lobby
Objective
Gain entry.
Complications
- Security barricades
- Civilian refugees
- Locked elevators
- Enemy sentries
The lobby battle announces the heroes’ arrival.
From this point forward the defenders know they’re coming.
Floors Two Through Four
Objective
Gather intelligence.
The defenders are still organized.
Possible encounters include:
- Communications centers
- Surveillance rooms
- Computer systems
- Captured witnesses
Players may discover:
- Hostage locations
- Enemy numbers
- Bomb threats
- Villain objectives
Floors Five Through Seven
Objective
Break organized resistance.
This is where the fighting becomes serious.
Features include:
- Barricaded hallways
- Kill zones
- Booby traps
- Reinforced offices
These levels should feel like urban warfare compressed into a single structure.
Floor Eight
Civilian Complications
The heroes discover survivors.
Possible dilemmas include:
- Injured office workers
- Hostages rigged with explosives
- Panicked civilians
- Enemy agents disguised as victims
The floor introduces moral decisions while consuming valuable time.
Every minute spent helping civilians allows enemies above to prepare.
Floor Nine
Vertical Combat
Now the battle moves upward.
Possible locations include:
- Stairwells
- Maintenance shafts
- Exterior window-cleaning platforms
- Fire escapes
- Elevator tops
Characters are no longer fighting across rooms.
They’re fighting across height.
Falling becomes as dangerous as gunfire.
Floor Ten
Boss Encounter
The enemy leader waits here.
Suggestions include:
- Terrorist mastermind
- Alien commander
- Cult high priest
- Cyborg warlord
- Supervillain lieutenant
The confrontation should reveal the true objective behind the occupation of the tower.
The Roof
Extraction Zone
Just because the villain is defeated doesn’t mean the mission is over.
New complications arrive:
- Enemy reinforcements
- Helicopter gunships
- Bomb countdowns
- Failing structural supports
- Incoming air strikes
The heroes must hold the roof long enough for extraction.
Success is measured not only by defeating the enemy but by escaping alive.
Final Tactical Thoughts
The appeal of building-clearance adventures lies in uncertainty.
Players cannot see the entire battlefield. They must earn information one room at a time. Every floor becomes its own miniature adventure. Every doorway presents a gamble. Every stairwell promises danger.
Whether your inspiration comes from Die Hard, Dredd, The Raid, Rainbow Six, or a dozen pulp magazines from decades past, the formula remains timeless:
A dangerous building.
A determined team.
Enemies above.
No easy way out.
Load fresh magazines, check your corners, and watch those doorways.
The Crimson Tower awaits. Mission ready. Tuesday approved.
If you would like to revisit past articles, look no further than the Geek Opera Index!
Duck the Alley Apples!