---
title: "Claude Sonnet 5 vs GPT-5.6 Terra | OpenRA arena | Evals by Jetty"
url: https://evaljetty.com/openra/games/rr-sonnet5-gpt56terra-g1.html
description: "GPT-5.6 Terra destroyed the enemy base. Watch the full game with both models' reasoning."
updated: 2026-09-28
publisher: Jetty (https://jetty.io)
---

Round robin · rr-sonnet5-gpt56terra-g1

# Claude Sonnet 5 vs GPT-5.6 Terra

GPT-5.6 Terra destroyed the enemy base after 7.8 game-minutes · 12.2 min wall clock

[Jetty trajectory](https://jetty.io/jettygrowthteam/openra-arena-match/0bde81b2)
[Replay (.orarep)](https://evaljetty.com/openra/media/rr-sonnet5-gpt56terra-g1.orarep)
[Decision log](https://evaljetty.com/openra/runs/rr-sonnet5-gpt56terra-g1/decisions.jsonl)
[Runtime config](https://evaljetty.com/openra/runs/rr-sonnet5-gpt56terra-g1/runtime_config.json)

LOSS ukraine · west

Claude Sonnet 5

anthropic/claude-sonnet-5

Value destroyed$7,700Value lost$13,200
Units killed / lost43 / 29Buildings killed / lost0 / 9
Peak army$2,700Orders issued92
Decision turns (failed)59 (0)Mean latency4.7sModel cost$0.399

WIN england · east

GPT-5.6 Terra

openai/gpt-5.6-terra

Value destroyed$13,200Value lost$7,700
Units killed / lost29 / 43Buildings killed / lost9 / 0
Peak army$5,800Orders issued91
Decision turns (failed)59 (0)Mean latency3.7sModel cost$0.455

## Decision timeline

What each model saw as its situation and what it ordered, every 8 game-seconds. Click a turn to jump the video there.

## Decision timeline

Every 8 game-seconds each model received a text briefing and replied with its reasoning and commands. Time is game time.

- **0:00 Claude Sonnet 5**: Deploy MCV to start base, then begin economy build.
- **0:00 GPT-5.6 Terra**: Deploy immediately and begin the standard economic opening with power, then refinery and barracks.
- **0:08 Claude Sonnet 5**: Start economy: power plant then refinery, then barracks.
- **0:08 GPT-5.6 Terra**: Construction Yard is deployed and the first power plant should be ready or nearly ready. Place it immediately, then establish refinery income and infantry scouting.
- **0:16 Claude Sonnet 5**: Place power plant, start ore refinery next, keep economy growing.
- **0:16 GPT-5.6 Terra**: Construction Yard is deployed; begin the standard opening by building power immediately, then place it and unlock the refinery.
- **0:24 Claude Sonnet 5**: Continue economy buildup: refinery, barracks, more power as needed.
- **0:24 GPT-5.6 Terra**: Construction Yard is deployed and the first power plant is ready. Place it immediately and begin the refinery to establish income.
- **0:32 Claude Sonnet 5**: Continue economy buildup while proc finishes. Queue power and barracks next.
- **0:32 GPT-5.6 Terra**: Power is online and the immediate priority is establishing ore income. Start the first refinery now, then place it and begin barracks/second refinery production next turn.
- **0:40 Claude Sonnet 5**: Proc is building. Once done, queue power and barracks. No units yet to act.
- **0:40 GPT-5.6 Terra**: The first refinery is still under construction. I will place it immediately when ready, then establish barracks and vehicle production while expanding ore income.
- **0:48 Claude Sonnet 5**: Proc is building. Queue barracks and power next, prepare for expansion.
- **0:48 GPT-5.6 Terra**: The first refinery is nearly ready and cash is healthy. I will place it immediately, establish infantry production, and begin scouting toward the likely enemy position.
- **0:56 Claude Sonnet 5**: Proc is nearly done, power plant building. Let's queue barracks next for infantry production and keep economy going.
- **0:56 GPT-5.6 Terra**: First refinery is nearly complete and the barracks is queued behind it. I will place the refinery as soon as it finishes, then establish infantry scouting and expand into vehicle production.
- **1:04 Claude Sonnet 5**: Place the ready ore refinery near base, keep building power and barracks. Economy first.
- **1:04 GPT-5.6 Terra**: First refinery is nearly complete and the barracks is queued behind it. Place the refinery immediately to start income, then use the barracks for early scouting infantry.
- **1:12 Claude Sonnet 5**: Continue economic buildup: barracks and power plant are queued. Once done, build war factory and start producing tanks.
- **1:12 GPT-5.6 Terra**: The refinery is ready and must be placed immediately to start income; the barracks is already constructing behind it. Once the barracks completes, begin infantry production and add a war factory/refinery depending on funds.
- **1:20 Claude Sonnet 5**: Place barracks, continue power plant, queue proc and weap for economy and army buildup.
- **1:20 GPT-5.6 Terra**: The first refinery is online and the barracks is nearing completion. I will place it immediately when ready, begin infantry production, then expand with a second refinery and war factory.
- **1:28 Claude Sonnet 5**: Base is building up nicely with weap, proc, powr in queue. Continue economy expansion and start training infantry to defend while production ramps up.
- **1:28 GPT-5.6 Terra**: Barracks is ready and economy has room for a second refinery. I will establish infantry production immediately while expanding ore income, then transition to a War Factory.
- **1:36 Claude Sonnet 5**: Buildings queued already (weap, proc, powr). Keep training infantry for defense and queue more once barracks free. Continue economy buildout.
- **1:36 GPT-5.6 Terra**: Second refinery is underway and the barracks is now available. Queue a balanced infantry screen, rally them east to scout, then use the refinery income to transition into a War Factory.
- **1:44 Claude Sonnet 5**: Continue economy buildup, train more infantry, keep queues busy.
- **1:44 GPT-5.6 Terra**: Second refinery is nearing completion, which will strengthen income with a second harvester. I will place it immediately when ready, start the War Factory, and send the rifleman scouting east toward the likely enemy base while keeping the ore truck mining.
- **1:52 Claude Sonnet 5**: Base is developing well with weap, proc, and powr queued. Keep training infantry and prepare for tank production once war factory completes.
- **1:52 GPT-5.6 Terra**: Second refinery is nearing completion with the War Factory queued behind it. Continue scouting east toward the likely enemy start while preserving the rocket soldier near base.
- **2:00 Claude Sonnet 5**: Keep building queue running: weap almost done, then proc/powr. Train more infantry to build army while waiting for tanks.
- **2:00 GPT-5.6 Terra**: Second refinery is nearly ready and will be placed as soon as available; then start the War Factory. Continue scouting east toward the expected enemy location while keeping rocket infantry advancing together.
- **2:08 Claude Sonnet 5**: War factory almost done, proc and powr in queue. Keep infantry production going and prepare for tank production once weap finishes.
- **2:08 GPT-5.6 Terra**: Second refinery is ready and should be placed immediately to strengthen income. War Factory construction is underway; keep scouting east toward the likely enemy position while infantry production completes.
- **2:16 Claude Sonnet 5**: Weap ready to place; place it, keep building proc/powr, queue fix once weap placed, mass infantry near base and start rocket soldiers for anti-tank mix.
- **2:16 GPT-5.6 Terra**: Second refinery is online and the War Factory is building; maintain infantry output while the scouting force pushes toward the likely enemy start. Keep all combat units advancing east to locate and pressure the enemy base.
- **2:24 Claude Sonnet 5**: Continue building economy and defenses. Queue fix and start tank production once war factory free. Keep infantry ready.
- **2:24 GPT-5.6 Terra**: War Factory is still constructing and infantry production is fully queued. Continue scouting aggressively toward the likely enemy base while saving for a refinery/power expansion as income arrives.
- **2:32 Claude Sonnet 5**: Economy building up, need more power and refinery. Keep training rocket soldiers and infantry. Once fix is done, start heavy tank production. Group idle infantry for defense.
- **2:32 GPT-5.6 Terra**: War Factory construction is underway while our infantry force continues scouting toward the likely enemy base. Keep infantry production continuous, reinforce with rockets when funds allow, and preserve cash for vehicle production once the factory completes.
- **2:40 Claude Sonnet 5**: Economy building underway (proc, fix, powr in queue). Keep infantry idle near base defending until army bigger, and queue more units to keep production busy.
- **2:40 GPT-5.6 Terra**: Our infantry spearhead is nearing the likely northeast enemy start with no resistance yet. Finish and place the War Factory, keep infantry production flowing, and press the entire army toward the enemy base location.
- **2:48 Claude Sonnet 5**: Economy still building (proc, fix, powr). I have 16 infantry idle - should group them and prepare to move toward enemy once tanks arrive. Keep production queues full and add power/harvester.
- **2:48 GPT-5.6 Terra**: War Factory is nearly complete while infantry are advancing toward the likely enemy start. Keep pressure moving east and preserve cash for immediate vehicle production once the factory is placed.
- **2:56 Claude Sonnet 5**: Economy building; keep infantry grouped and defending base while proc2/fix finish. Continue training e3/e1 and queue tanks once weap free.
- **2:56 GPT-5.6 Terra**: War Factory is nearly complete while our infantry column has reached the enemy approach with no resistance spotted. Keep the entire combat force advancing toward the likely enemy base and rally future infantry forward.
- **3:04 Claude Sonnet 5**: Power too low is slowing everything. Queue another power plant and keep economy/army building. Group idle infantry for defense while waiting for tanks.
- **3:04 GPT-5.6 Terra**: War Factory is ready, but placing it will require more power. I will cancel the duplicate factory, place the first one, restore power, and keep the infantry push moving toward the enemy start.
- **3:12 Claude Sonnet 5**: Power still critically low; already building powr, fix, powr in queue. Keep infantry training going and group idle army for defense while economy catches up. Wait before attacking until power fixed and tanks available.
- **3:12 GPT-5.6 Terra**: Power plant is still building and cash is insufficient for vehicles. Keep the infantry pressure moving toward the likely enemy base while the new power plant finishes, then restore full production speed and begin tank production.
- **3:20 Claude Sonnet 5**: Power still building; keep economy going, group infantry defend, wait for power/tanks before attacking.
- **3:20 GPT-5.6 Terra**: Power plant is nearly complete and must be placed immediately to restore production speed. Our advancing infantry screen is close to the likely enemy start, so keep pressure east while the economy resumes and prepare refinery expansion.
- **3:28 Claude Sonnet 5**: Place ready power plant to fix low power. Continue production queue. Keep infantry grouped defending base for now.
- **3:28 GPT-5.6 Terra**: A power plant is ready and must be placed immediately to restore production speed. Our infantry spearhead is near the likely enemy start, so keep it advancing while the refinery construction continues and start vehicle production if funds permit.
- **3:36 Claude Sonnet 5**: Enemy base far west; I have a decent infantry force idle. Attack the visible enemy scout and start pushing west while continuing production.
- **3:36 GPT-5.6 Terra**: Our spearhead has reached the likely enemy start without contact, so push all available infantry east to reveal and destroy the enemy base while tank production continues. Economy is temporarily empty but two refineries and queued units will convert incoming ore into pressure.
- **3:44 Claude Sonnet 5**: Army pushing west toward enemy base, no enemy visible yet. Keep economy growing, fix/powr production ongoing, and continue training infantry. Queue more tanks once war factory frees up.
- **3:44 GPT-5.6 Terra**: The second refinery is progressing and both production lines are already queued, while our scouting infantry is advancing toward the likely enemy start. Keep pressure northeast and consolidate stragglers behind the forward force.
- **3:52 Claude Sonnet 5**: Army is grouped near (79-81,13-15), engage nearby enemy e3 and continue attack_move westward toward enemy base. Keep production running.
- **3:52 GPT-5.6 Terra**: Our scouting force has reached enemy infantry near the northeast approach, while our economy and production queues are already committed. Keep pressure moving toward the likely enemy base and place the refinery as soon as it completes.
- **4:00 Claude Sonnet 5**: Army near (72-74,18-21), enemy weak unit visible. Push west toward enemy base at (12,16), keep economy building and training more infantry.
- **4:00 GPT-5.6 Terra**: Our second refinery and first light tank are nearly complete, while the infantry screen is advancing toward the likely enemy northeast base. Keep all production queued and push the scattered rifle force east to engage scouts and reveal structures.
- **4:08 Claude Sonnet 5**: Continue pushing army west toward enemy base at (12,16). Keep production going, cash is low so let queue continue.
- **4:08 GPT-5.6 Terra**: Second refinery is nearing completion and production queues are committed despite no cash. Push the forward rifle scouts northeast toward the suspected enemy start while keeping home defenders and the tank near base until reinforcements emerge.
- **4:16 Claude Sonnet 5**: Continue push west toward enemy base, kill remaining infantry, keep production going. Queue more tanks once fix finishes.
- **4:16 GPT-5.6 Terra**: Our forward rifles have found an enemy infantry screen near the center-east, while the first light tank is ready to reinforce. Keep production queued, finish the refinery for stronger income, and use the tank with nearby infantry to clear and scout toward the enemy start.
- **4:24 Claude Sonnet 5**: Army near (54,28) engaging enemy tank; push forward toward enemy base at (12,16). Keep production going.
- **4:24 GPT-5.6 Terra**: Our forward tank is badly damaged and facing a large enemy infantry/rocket screen, so it should retreat while new production continues. The refinery will strengthen income once ready; preserve units and rally reinforcements toward the central approach.
- **4:32 Claude Sonnet 5**: Army is grouped near (46-49,25-29). Continue push toward enemy base at (12,16). Keep production going, queue tanks once fix ready.
- **4:32 GPT-5.6 Terra**: The refinery is nearly complete and production queues are saturated despite no immediate cash. I will use the surviving infantry to scout and contest the central route toward the enemy while the new light tanks rebuild our field force.
- **4:40 Claude Sonnet 5**: Army is pushing toward enemy at (12,16), currently around (36-39,23-27). Keep advancing and continue production. Cash is 0 so wait for income, keep queues going.
- **4:40 GPT-5.6 Terra**: Our refinery and first tank are nearly complete, with both production queues fully committed. Continue scouting northeast toward the likely enemy base while keeping harvesters mining and prepare to place the refinery immediately next turn.
- **4:48 Claude Sonnet 5**: Army is near (28,20s) advancing west toward enemy base at (12,16). Continue attack move, keep production flowing at home.
- **4:48 GPT-5.6 Terra**: The refinery and first light tank are about to complete while all available cash is committed to production. I will rally new forces northeast toward the likely enemy base and keep production queues running.
- **4:56 Claude Sonnet 5**: My army is near enemy base at (23,15)/(21,14). Push attack into enemy refinery and harvesters, keep production going.
- **4:56 GPT-5.6 Terra**: A refinery is ready and must be placed to restore income momentum. Enemy infantry are clustered directly beside our ore operation, so the tank and rifleman will engage while harvesters are pulled back from danger.
- **5:04 Claude Sonnet 5**: Army is already near enemy base fighting. Push attack_move onto remaining enemy buildings to finish them off, keep reinforcements coming from barracks/factory.
- **5:04 GPT-5.6 Terra**: Enemy infantry are swarming the refinery area while our vehicle and infantry production is already queued. Send idle harvesters back to ore and focus the light tank and rifleman on the enemy rocket soldier first.
- **5:12 Claude Sonnet 5**: Our units are already near enemy base with heavy wounds; focus fire on their refineries to cripple economy while pushing home reinforcements. No cash so let production continue passively.
- **5:12 GPT-5.6 Terra**: Enemy infantry are still inside the refinery area, so the surviving tank and rifleman must focus their rocket soldier immediately while production completes and ore is processed. Keep the harvesters mining and avoid sending the damaged tank away from base defense.
- **5:20 Claude Sonnet 5**: My infantry group is deep in enemy territory near their weak refineries. Push attack to finish off proc #152 (3% hp) and continue harassing. Keep production running and cancel excess queued infantry to save cash for economy buildings.
- **5:20 GPT-5.6 Terra**: Enemy rifle infantry are directly on our refinery line, while our remaining combat force is tiny and the damaged refinery is critical. Focus-fire the closest infantry cluster and keep harvesters mining so queued tanks and infantry can emerge.
- **5:28 Claude Sonnet 5**: Continue pressing the weakened enemy base near (20,18); consolidate wounded units and push new reinforcements. Keep economy running with harvesters and power.
- **5:28 GPT-5.6 Terra**: Our production queues are saturated but cash is constrained; the critically damaged refinery must be repaired as soon as ore unloads. The small local force will eliminate the exposed enemy infantry while the damaged tank stays back.
- **5:36 Claude Sonnet 5**: Economy fine, keep training infantry and pushing toward enemy base. Move idle units west to join the front and continue production.
- **5:36 GPT-5.6 Terra**: Production queues are already saturated, while the damaged refinery is being repaired. Keep the crippled tank home and send the healthier mixed force northeast to scout toward the suspected Soviet base.
- **5:44 Claude Sonnet 5**: Cash is at zero with a massive backlog queued; nothing will produce until ore income builds up. Place the ready service depot, keep harvesters mining, and regroup scattered infantry rather than issuing costly new orders.
- **5:44 GPT-5.6 Terra**: Our economy is fully committed with three harvesters and multiple light tanks/infantry already queued. Continue pushing the available force toward the likely enemy base while keeping the critically damaged tank at home and routing new production forward.
- **5:52 Claude Sonnet 5**: Cash is $0 with massive infantry backlog and low power. Let existing power plants finish building to fix power issue; can't afford new production now. Regroup idle units near base for defense.
- **5:52 GPT-5.6 Terra**: Our forward force is nearing the enemy approach and should eliminate the visible rocket soldier while continuing toward the likely base. The critically damaged refinery must be repaired; production queues are already fully committed and harvesters should keep mining.
- **6:00 Claude Sonnet 5**: Power still low, three powr plants building. Keep infantry queue going, gather idle units at base, continue.
- **6:00 GPT-5.6 Terra**: Our forward force is probing toward the enemy’s likely northeast base while three refineries sustain income. Keep the damaged refinery repaired, preserve the nearly destroyed home tank, and concentrate combat units eastward until enemy structures are revealed.
- **6:08 Claude Sonnet 5**: Power still low with huge infantry backlog stalling everything. Focus economy: let power finish, then build tanks. Group idle infantry to defend base while economy stabilizes.
- **6:08 GPT-5.6 Terra**: Our forward force is advancing northeast toward the likely Soviet base, while the damaged refinery remains the immediate economic risk. Keep the tank queues running, consolidate the scattered attack group, and get the crippled home tank safely back behind the base.
- **6:16 Claude Sonnet 5**: Place ready power plant to fix power deficit. Keep infantry queue as-is (huge backlog, don't add more). Defend against enemy tank scout with idle infantry near base.
- **6:16 GPT-5.6 Terra**: Our forward force has reached the enemy start and exposed a power plant; concentrate on it while the trailing army continues into the base. Keep the critically damaged tank safely at home and maintain refinery repairs.
- **6:24 Claude Sonnet 5**: Place ready power plant, keep economy growing with second refinery, and start tank production from war factory since infantry backlog is huge already.
- **6:24 GPT-5.6 Terra**: Our forward force is at the enemy start and can remove their remaining visible power while reinforcements converge. Keep the damaged refinery repaired and the nearly finished tank production flowing into the assault.
- **6:32 Claude Sonnet 5**: Massive infantry backlog remains queued at 0%, but production is capped one at a time per category so it's fine—just wastes queue slots visually. Focus on getting proc#2 done, tanks rolling, and defend base with current infantry while waiting for a bigger army.
- **6:32 GPT-5.6 Terra**: Our forward force is already spread across the enemy approach and their base power is exposed. Keep pressure on the visible power plant while replacing losses and expanding ore income; pull the nearly destroyed tank back.
- **6:40 Claude Sonnet 5**: Cash is 0 so can't queue more; focus power since low power slows production. Let idle infantry defend base, keep waiting for tanks and proc.
- **6:40 GPT-5.6 Terra**: Our forward force is at the enemy approach but has lost sight of their base; keep pressure toward the confirmed start while the economy recovers. The critically damaged light tank should withdraw, and all harvesters must stay mining to fund the refinery and continuous queues.
- **6:48 Claude Sonnet 5**: Cash is zero so production stalls; need to wait for income. Enemy infantry group nearby at (89-90,12) threatens our east side. Keep defenders on hold and let queues finish as ore comes in.
- **6:48 GPT-5.6 Terra**: Our forward infantry and rockets are at the enemy start area, while reinforcements are en route. Commit all combat units to a concentrated attack-move through the confirmed enemy base location and keep production/rallies feeding the assault.
- **6:56 Claude Sonnet 5**: Power is critical at 0 made - need to prioritize powr build. Enemy infantry group approaching from west, keep my few units defensive near base rather than engaging outnumbered. Continue tank production once power resumes.
- **6:56 GPT-5.6 Terra**: Our forward force is at the enemy start and should keep pressing despite lost vision. Keep production queued, mine continuously, repair the crippled refinery, and send reinforcements east while the 4% tank withdraws.
- **7:04 Claude Sonnet 5**: Power still critical, must prioritize finishing power plant. Enemy infantry group is near my base at (91,12), close combat range. Pull my rocket soldiers together defensively rather than engaging piecemeal, and keep production going since power plant is at 53%.
- **7:04 GPT-5.6 Terra**: Our forward infantry and rockets are already at the exposed enemy base; focus fire the damaged Construction Yard for an immediate win while reinforcements continue east. Production queues are full and the damaged refinery remains under repair.
- **7:12 Claude Sonnet 5**: Enemy infantry/tank group is right at our doorstep near (91,12). We have 0 power hurting production. Need to build power plant immediately and defend with available units while tanks finish training.
- **7:12 GPT-5.6 Terra**: Our eastern assault is inside the enemy base area and their visible barracks is the priority target. Keep pressure on it while reinforcements and queued light tanks arrive; repair the critically damaged refinery immediately.
- **7:20 Claude Sonnet 5**: Low power is hurting production. Enemy group is weak and nearby - defend with what we have. Try building power plant again, and keep tank production going.
- **7:20 GPT-5.6 Terra**: Our assault is inside the enemy base and the visible War Factory is the priority; destroy it immediately while reinforcements continue east. Keep damaged units out of the fight and harvesters working while the refinery repair completes.
- **7:28 Claude Sonnet 5**: Enemy infantry group is right next to my base at (92,12), weak/damaged. Continue building tanks and try to get power plant via building queue since power is 0. Focus economy and defense.
- **7:28 GPT-5.6 Terra**: Our assault is inside the enemy base and their damaged War Factory is exposed. Finish it with the nearby force while reinforcements continue east; preserve the critically damaged tank and refinery.
- **7:36 Claude Sonnet 5**: No construction yard visible - likely destroyed. Can't build power without it. Focus on keeping harvesters safe and see if any production is possible.
- **7:36 GPT-5.6 Terra**: Our assault is inside the exposed enemy base, with two remaining visible structures that should be focused down immediately. Place the ready refinery to strengthen income while local infantry, rockets, and tanks finish the enemy economy and depot; withdraw critically damaged tanks.
- **7:44 Claude Sonnet 5**: No construction yard, no combat units, enemy swarm nearby. Situation is dire - just try to keep harvesters alive and away from enemy.
- **7:44 GPT-5.6 Terra**: Our forward infantry force is entrenched at the enemy start and the Service Depot is the only visible remaining target. Finish it while damaged tanks retreat, and keep the fresh light tanks rallied toward the assault corridor.

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Source: https://evaljetty.com/openra/games/rr-sonnet5-gpt56terra-g1.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms