Combat
Combat in Terminal Descent is a turn-based system where ZERO uses loaded Programs and combat commands to fight Intrusion Countermeasures (IC) — hostile security programs that patrol The Lattice. Combat is one of several approaches to obstacles; players can also use stealth, hacking, or social skills to bypass encounters.
Core Mechanics
Turn Structure
Combat is turn-based. Each turn, the player selects a combat command, then all IC in the encounter act. Turn order is determined by speed:
- Player selects action (ATTACK, DEFEND, EVADE, COUNTER, CLOAK, or use a program)
- Action resolves
- Each IC acts based on its behavior pattern
- Status effects tick (buffs, debuffs, duration)
- Turn counter increments
Damage Formula
Base Attack Power = program.damage + (combat_skill × 2) + deckMod Defense Percent = min(0.80, defense / (defense + 50)) If attack ≥ defense: baseDamage = attack × (1 - defensePercent) Else (attacker weaker): baseDamage = (attack² ) / (defense + 50) Final Damage = baseDamage × effectiveness × critical × chain × mastery × variance(±10%)
Key design principles:
- No zero damage — minimum 1 damage always applies
- Defense is percentage-based, not flat subtraction
- Stats grow linearly (Level 6 IC is roughly 3× stronger than Level 1, not 30×)
- The 80% defense cap means 20% of damage always gets through
Critical Hits
Critical strikes deal 2.0× damage (2.5× with Precision Core upgrade).
Critical chance calculation:
- Base: 10%
- + Analysis skill × 2% (max +12% at level 6)
- + Program Mastery Tier 5+: +2%
- + Program Mastery Tier 10: +5%
- + Operator Rank (per 50): +0.75%
- + Assault Frame Precision Core: +10%
- + TAUNT command: next ATTACK is guaranteed critical
Hard cap: 35%
Defense and Firewall
Defense Rating = (firewall × 5) + program.defense + deckMod
Cyberdeck firewall level directly impacts survivability:
- FW 1 = 5 defense rating
- FW 3 = 15 defense rating
- FW 6 = 30 defense rating
Neural Damage (BlackICE specialty) bypasses normal defense:
neuralDmg = blackice.neuralDmg × (1 - player.firewall × 0.05)
Firewall reduces neural damage by 5% per level (max 30% at FW 6).
Combat Commands
| Command | Effect | Notes |
|---|---|---|
| ATTACK | Deal damage using loaded offensive program | Primary damage action. Generates HEAT. |
| DEFEND | Reduce incoming damage this turn | Damage reduction based on defense rating. Sets up Mirror Protocol. |
| EVADE | Attempt to dodge all incoming attacks | Success based on speed + Stealth skill. Sets up Breach/Ghost Protocol. |
| COUNTER | Riposte the next attack received | Must be hit to trigger. Reflects portion of damage. Sets up Mirror/Siege Protocol. |
| CLOAK | Become invisible for several turns | Duration based on Stealth skill. IC cannot target you. Breaks on attack. |
| SPOOF | Fake credentials to confuse IC | Can cause IC to ignore you or attack allies. Social/Intrusion check. |
Protocol Chains
Executing specific command sequences triggers powerful combo effects:
| Chain | Sequence | Bonus |
|---|---|---|
| Breach Protocol | ATTACK → EVADE → ATTACK | +30% damage on final hit |
| Mirror Protocol | DEFEND → COUNTER → ATTACK | +50% damage, 100% counter reflect |
| Ghost Protocol | EVADE → CLOAK → ATTACK | +100% damage (2×), 0 HEAT generated |
| Siege Protocol | ATTACK → ATTACK → COUNTER | +25% damage to ALL IC in node |
Secret Chains
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Important: Chain multipliers stack with critical hits (e.g., Breach crit = 1.30 × 2.0 = 2.60×) but do NOT stack with each other.
IC Stat Growth
IC stats scale with level using a linear growth formula:
stat(level) = baseStat × (1 + (level - 1) × growthRate)
| Stat | Growth Rate Per Level |
|---|---|
| HP | +20% |
| Attack | +15% |
| Defense | +12% |
| Speed | +8% |
| Evasion | +5% |
| Detection | +10% |
This means a Level 5 Sentry has roughly 1.8× the stats of a Level 1 Sentry — challenging but not overwhelming.
Combat and HEAT
Combat actions affect HEAT:
- Killing IC: +3 to +8 HEAT (varies by IC type)
- Using aggressive programs: +1 to +3 HEAT
- Ghost Protocol chain: 0 HEAT generated
- Bypassing IC entirely (stealth/social): No HEAT gain
- Mercy Protocol: Reduced HEAT vs. killing
Players pursuing the Ghost Protocol ending must keep HEAT ≤15 throughout Act III, making stealth and non-combat approaches essential.
Combat Strategy
Early Game
- Focus on learning IC patterns through ANALYZE before engaging
- EVADE is more reliable than DEFEND at low levels
- Conserve programs — memory slots are limited
Mid Game
- Protocol chains become essential for harder IC
- Ghost Protocol (EVADE → CLOAK → ATTACK) is the most efficient chain: double damage, zero HEAT
- Upgrade Cyberdeck processor and memory to load stronger programs
Late Game
- BlackICE requires high firewall to survive neural damage
- Hunter IC adapts to repeated strategies — vary your approach
- Boss encounters have multiple phases; conserve resources