---
title: "Claude Sonnet 5 vs GPT-5.6 Terra | OpenRA arena | Evals by Jetty"
url: https://evaljetty.com/openra/games/rr-sonnet5-gpt56terra-g3.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-g3

# Claude Sonnet 5 vs GPT-5.6 Terra

GPT-5.6 Terra destroyed the enemy base after 5.3 game-minutes · 8.2 min wall clock

[Jetty trajectory](https://jetty.io/jettygrowthteam/openra-arena-match/8d343c33)
[Replay (.orarep)](https://evaljetty.com/openra/media/rr-sonnet5-gpt56terra-g3.orarep)
[Decision log](https://evaljetty.com/openra/runs/rr-sonnet5-gpt56terra-g3/decisions.jsonl)
[Runtime config](https://evaljetty.com/openra/runs/rr-sonnet5-gpt56terra-g3/runtime_config.json)

LOSS russia · west

Claude Sonnet 5

anthropic/claude-sonnet-5

Value destroyed$200Value lost$11,850
Units killed / lost2 / 3Buildings killed / lost0 / 12
Peak army$300Orders issued45
Decision turns (failed)40 (0)Mean latency4.7sModel cost$0.242

WIN germany · east

GPT-5.6 Terra

openai/gpt-5.6-terra

Value destroyed$11,850Value lost$200
Units killed / lost3 / 2Buildings killed / lost12 / 0
Peak army$2,700Orders issued42
Decision turns (failed)40 (0)Mean latency3.3sModel cost$0.287

## 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 order.
- **0:00 GPT-5.6 Terra**: Deploy immediately at the eastern start, then establish the standard power/refinery opening and scout toward the likely enemy base in the west.
- **0:08 Claude Sonnet 5**: Construction yard deployed. Start economic buildup with power plant then refinery.
- **0:08 GPT-5.6 Terra**: Construction Yard is deployed. Start the standard economy opening immediately with power, then refinery and infantry scouting.
- **0:16 Claude Sonnet 5**: Place power plant, start ore refinery, keep building economy.
- **0:16 GPT-5.6 Terra**: Construction Yard is deployed with ample starting cash. Place the ready power plant immediately, then begin the first refinery to establish income.
- **0:24 Claude Sonnet 5**: Continue economy build: proc first for income, then barracks.
- **0:24 GPT-5.6 Terra**: Construction Yard and initial power are established. Start the first refinery immediately to unlock income, then use the next turns for barracks and scouting.
- **0:32 Claude Sonnet 5**: Continue economic buildup while proc finishes. Queue barracks next.
- **0:32 GPT-5.6 Terra**: First refinery is still under construction. I will place it as soon as it completes, then immediately establish infantry production and scouting toward the western enemy start.
- **0:40 Claude Sonnet 5**: Continue building economy: proc and barr underway. Queue power plant next for power safety and start planning defenses.
- **0:40 GPT-5.6 Terra**: Ore Refinery is still building and will be ready shortly. I will place it next turn, then immediately establish barracks production and scout west toward the expected enemy base.
- **0:48 Claude Sonnet 5**: Continue economy buildup: proc, powr, barr already queued. Wait for completion.
- **0:48 GPT-5.6 Terra**: First refinery is still under construction and power is ample. Place it as soon as available, then immediately start the barracks for scouting infantry.
- **0:56 Claude Sonnet 5**: Continue base setup; proc almost ready, powr and barr queued. Nothing else to do this tick.
- **0:56 GPT-5.6 Terra**: First refinery is nearly complete and the barracks is queued behind it. Place the refinery immediately to begin income, then use the barracks for scouting infantry.
- **1:04 Claude Sonnet 5**: Place ore refinery near base to start economy, continue building queue.
- **1:04 GPT-5.6 Terra**: The first refinery is ready and must be placed immediately to start income. The barracks is already building, so I will establish the refinery and prepare infantry production next.
- **1:12 Claude Sonnet 5**: Place ready power plant, keep building barracks, queue proc #2 and war factory next for economy and army buildup.
- **1:12 GPT-5.6 Terra**: First refinery is online and the barracks is nearing completion. Keep the harvester mining; place the barracks immediately next turn and follow with a War Factory.
- **1:20 Claude Sonnet 5**: Continue economy build-up: barracks and proc are queued. Keep building power and expand.
- **1:20 GPT-5.6 Terra**: Barracks is ready; place it immediately and begin a War Factory while using the barracks to create a scouting force. The enemy is likely far west, so infantry will advance west to reveal the map and locate their base.
- **1:28 Claude Sonnet 5**: Economy building phase, proc and barracks already queued. Continue with power and prepare for war factory next.
- **1:28 GPT-5.6 Terra**: War Factory is under construction and the barracks is ready to begin scouting infantry. I will rally scouts west toward the suspected Soviet start while keeping the harvester mining and saving enough flow to finish the factory.
- **1:36 Claude Sonnet 5**: Continue base buildup: proc and powr and barr already queued. Let them finish, plan war factory next.
- **1:36 GPT-5.6 Terra**: War Factory is nearing completion and the barracks is active. I will scout west toward the likely Soviet start while continuing infantry production and keeping the harvester mining.
- **1:44 Claude Sonnet 5**: Economy is building. Let proc/powr/barr finish, then queue war factory and start training infantry for defense/attack.
- **1:44 GPT-5.6 Terra**: War Factory is nearly ready; I will place it immediately next turn and begin vehicle production. Infantry continue scouting west while the first harvester mines.
- **1:52 Claude Sonnet 5**: Place the ready proc, keep building power and barracks queued, plan war factory next.
- **1:52 GPT-5.6 Terra**: War Factory is nearly complete while infantry production remains queued. Keep the scout force pushing west toward the likely enemy base and place the factory immediately once ready next turn.
- **2:00 Claude Sonnet 5**: Continue building economy and army infrastructure. Weap and powr are queued, need barracks too for infantry support.
- **2:00 GPT-5.6 Terra**: War Factory is nearly complete while the scouting infantry has stalled short of the enemy side. Continue the westward attack-move, finish current infantry, then place the factory and begin vehicle production as funds permit.
- **2:08 Claude Sonnet 5**: Continue economy buildup, queue is busy with weap and barr. Let production continue; nothing new to add until buildings finish.
- **2:08 GPT-5.6 Terra**: War Factory is about to complete, so I will place it immediately when ready and use the existing infantry/rocket group to continue scouting toward the likely Soviet start. Cash is too low for more production until the harvester returns ore.
- **2:16 Claude Sonnet 5**: Continue building economy and army infrastructure; queue units once war factory and barracks ready.
- **2:16 GPT-5.6 Terra**: War Factory is ready and must be placed immediately. Our infantry spearhead should continue directly toward the likely enemy base while the new factory enables tank production as soon as income arrives.
- **2:24 Claude Sonnet 5**: Multiple buildings queued already; economy strong. Continue building, prepare for tank production once weap finishes.
- **2:24 GPT-5.6 Terra**: War Factory is online but funds are tied up in ore delivery; keep the harvester mining and consolidate all infantry toward the likely Soviet base. Spend the next income on a second refinery and continuous light tanks.
- **2:32 Claude Sonnet 5**: Multiple buildings in queue already (weap almost done, barr and powr in queue). Let production continue, plan tanks and infantry once ready.
- **2:32 GPT-5.6 Terra**: Our infantry and rocket force is advancing west toward the likely enemy base while the refinery converts stored ore. Keep the army concentrated and the harvester actively mining; spend incoming cash on a second refinery immediately.
- **2:40 Claude Sonnet 5**: War factory almost done; barracks and power building queued. Once weap finishes, add fix and start tank production. Keep economy running.
- **2:40 GPT-5.6 Terra**: Our infantry force is advancing across the map toward the likely enemy start while the economy is temporarily cash-starved. Build power first so a second refinery can be placed immediately once ore unloads, and keep the harvester mining.
- **2:48 Claude Sonnet 5**: Place war factory, keep queues going. Add proc for economy and continue building barracks/power.
- **2:48 GPT-5.6 Terra**: Forward infantry are scouting toward the likely enemy start while the first harvester should soon fund expansion. Place the completed power plant and immediately start a second refinery for stronger income.
- **2:56 Claude Sonnet 5**: Enemy infantry spotted very close to my base, could threaten harvesters/buildings. Continue economy build-out and get barracks done to train defenders. Keep proc/powr queued.
- **2:56 GPT-5.6 Terra**: Our infantry force has reached the enemy approach and their War Factory is exposed at (15,14). Keep pressure on it while the second refinery completes, then convert income into tanks and harvesters.
- **3:04 Claude Sonnet 5**: Enemy infantry cluster is right next to my base at (19-20,14-16). I should train tanks from war factory for defense and continue economic builds. Keep production queues busy.
- **3:04 GPT-5.6 Terra**: Our forward infantry and rockets are already at the enemy War Factory and should finish it while the refinery completes. Keep pressure on their economy and immediately place the second refinery when ready to fund tanks and another harvester.
- **3:12 Claude Sonnet 5**: Enemy infantry cluster near my base with no defense. I need fix depot to unlock tanks from weap, and barracks for infantry defense. Continue building power/proc. Keep harvesters mining.
- **3:12 GPT-5.6 Terra**: Our forward infantry and rockets are pressuring the exposed enemy War Factory and Refinery; keep all available combat units focused there while the second Refinery finishes. Once income resumes, immediately expand vehicle production.
- **3:20 Claude Sonnet 5**: Enemy infantry group is close to my base at (19,15-17), threatening my structures. My war factory isn't ready yet. I should build a defense (tesla coil) and keep economy going while waiting for tanks.
- **3:20 GPT-5.6 Terra**: Our forward infantry force is at the enemy refinery and should finish it while scouting for the nearby war factory. Refinery production will complete soon; keep harvesting and maintain pressure on the exposed enemy base.
- **3:28 Claude Sonnet 5**: Enemy infantry swarm is dangerously close to my base with no combat units yet. Place the ready refinery, keep production going, and prioritize finishing defenses/barracks to get infantry out fast.
- **3:28 GPT-5.6 Terra**: Our infantry force is on the exposed enemy refinery and should finish it while the second refinery completes. Keep pressure on the enemy start and regroup scattered reinforcements westward.
- **3:36 Claude Sonnet 5**: Enemy infantry swarm near base is a big threat with no defenses ready yet. Place the ready power plant, keep production queues running, and prioritize finishing the Tesla Coil and barracks for defense.
- **3:36 GPT-5.6 Terra**: Our infantry force is inside the enemy base and their exposed War Factory is already at half health. Finish it immediately, keep the distant reinforcements advancing, and place the refinery as soon as it completes to restore economic momentum.
- **3:44 Claude Sonnet 5**: Enemy infantry swarm is right at our doorstep near (18,16-17), very dangerous with no combat units yet. Priority: place the ready power plant, keep building queue going, and get barracks/tesla coil done ASAP for defense.
- **3:44 GPT-5.6 Terra**: Our infantry is inside the exposed enemy base and their War Factory is nearly destroyed. Keep all nearby forces focused on eliminating visible structures while the refinery completes to restore income.
- **3:52 Claude Sonnet 5**: Enemy infantry swarm right next to base, no defenders yet. Need barracks online fast to train troops. Continue building queue and prepare defense once barracks ready.
- **3:52 GPT-5.6 Terra**: Our forward infantry are at the exposed enemy power plant and should finish it while reinforcements close in. The refinery is nearly complete; place it as soon as it becomes ready and keep the harvester mining.
- **4:00 Claude Sonnet 5**: Enemy infantry near my base but I have no combat units yet. Place the ready power plant, keep barracks/power building, and queue an ore silo for storage overflow. Once barracks finish, train infantry to defend.
- **4:00 GPT-5.6 Terra**: Our infantry is already at the enemy start area, so consolidate them and press through the likely base location while the second refinery completes. Keep the harvester mining and use the incoming income for uninterrupted vehicle production.
- **4:08 Claude Sonnet 5**: Enemy infantry swarm (13 units) is right next to our base with no combat units of our own yet. Barracks at 64% - need it fast. Place silo now, prioritize defense walls to block chokepoint, and get harvesters safe.
- **4:08 GPT-5.6 Terra**: Our forward infantry force is inside the exposed enemy base and should finish the Construction Yard immediately. Refinery is nearly ready, after which we need vehicle production and a stronger economy.
- **4:16 Claude Sonnet 5**: Enemy infantry swarm right at my base with fact damaged. Must place ready barr and brik wall immediately, then rush train e1/e3 for defense.
- **4:16 GPT-5.6 Terra**: Our forward infantry force is already inside the exposed enemy base and should finish its damaged Construction Yard immediately, then clear remaining power and storage. Keep the home rocket moving forward while the refinery completes for an economic boost.
- **4:24 Claude Sonnet 5**: No construction yard listed - it may have been destroyed. Enemy infantry swarm right at our base. Must train defenders immediately from barracks and use brik for defense.
- **4:24 GPT-5.6 Terra**: The enemy Construction Yard is down; finish the exposed barracks, power, and silo immediately while the rear reinforcements move west. The refinery will be ready shortly, then place it and use the income for tanks and more harvesters.
- **4:32 Claude Sonnet 5**: Enemy infantry swarm (14 units) near my base at (16,13-16). I have only 1 e3 alive and my Construction Yard already lost. Must mass-produce infantry from barracks and use brik wall as defense. Keep harvesters mining ore for economy.
- **4:32 GPT-5.6 Terra**: Our forward infantry force is already on top of the exposed enemy base, so finish the barracks and silo immediately while reinforcements move west. The refinery will complete shortly; place it and use the added income for continuous vehicle production.
- **4:40 Claude Sonnet 5**: No construction yard or barracks remains, production is crippled. Enemy infantry swarm nearby. Try to queue barracks to rebuild army production and keep harvesters mining.
- **4:40 GPT-5.6 Terra**: Our assault force is at the enemy base and has already destroyed most visible enemy structures. Keep all combat units attacking through the remaining wall and base area while the second refinery completes for economic recovery.
- **4:48 Claude Sonnet 5**: No construction yard left, enemy infantry overrunning base. Can't produce buildings without conyard. Focus on protecting harvesters and repairing what's left; nothing else productive is possible right now.
- **4:48 GPT-5.6 Terra**: Our assault is already inside the exposed enemy base and their remaining refinery and power plant are damaged. Keep all combat units pushing west to finish visible structures while the refinery completes for economic recovery.
- **4:56 Claude Sonnet 5**: No construction yard or barracks left, so I can't build anything new. Enemy infantry swarm is very close to my remaining buildings. Best I can do is keep harvesters mining and repair damaged buildings, hoping to survive; there's no army production available.
- **4:56 GPT-5.6 Terra**: Our western infantry force is inside the enemy base and can finish the exposed power plants while the second refinery expands income. I will place it immediately, queue another refinery, and send all available combat units toward the enemy start.
- **5:04 Claude Sonnet 5**: Base is nearly destroyed, no construction yard means no way to build anything new. Only proc and brik remain. Just keep harvesters mining to preserve some economy score, nothing else to do.
- **5:04 GPT-5.6 Terra**: Enemy base has been largely destroyed and only a damaged wall is currently visible; keep all forward infantry pressing into the west base area while refinery and tank queues complete. Cash is exhausted, so preserve production queues and use existing units to finish the enemy structures.
- **5:12 Claude Sonnet 5**: Base largely destroyed, only proc remains with no power. Enemy infantry swarming near base. Little I can do but try to preserve harvesters and proc; can't build without conyard.
- **5:12 GPT-5.6 Terra**: Our forward infantry has cleared most of the western enemy base, and no enemy buildings are currently visible. Keep pressure on the likely start area while continuing the tank and infantry production queues; the new refinery will strengthen income once placed.

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Source: https://evaljetty.com/openra/games/rr-sonnet5-gpt56terra-g3.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms