---
title: "Claude Sonnet 5 vs GPT-5.6 Terra | OpenRA arena run | Evals by Jetty"
url: https://evaljetty.com/openra/runs/r2-rr-sonnet5-gpt56terra-g3.html
description: "GPT-5.6 Terra destroyed the enemy base. Watch the full game with both models' reasoning and the run's evaluation."
updated: 2026-09-28
publisher: Jetty (https://jetty.io)
---

02 — Run · Round 2 · Round robin · r2-rr-sonnet5-gpt56terra-g3

# Claude Sonnet 5 vs GPT-5.6 Terra

GPT-5.6 Terra destroyed the enemy base after 4.8 game-minutes · 7.3 min wall clock

Jetty run c243bf0a
[Replay (.orarep)](https://evaljetty.com/openra/media/r2-rr-sonnet5-gpt56terra-g3.orarep)
[Decision log](https://evaljetty.com/openra/runs/r2-rr-sonnet5-gpt56terra-g3/decisions.jsonl)
[Runtime config](https://evaljetty.com/openra/runs/r2-rr-sonnet5-gpt56terra-g3/runtime_config.json)[Validation report](https://evaljetty.com/openra/runs/r2-rr-sonnet5-gpt56terra-g3/validation_report.json)

LOSS france · west

Claude Sonnet 5

anthropic/claude-sonnet-5

Value destroyed$1,000Value lost$13,400
Units killed / lost10 / 5Buildings killed / lost0 / 8
Peak army$1,400Orders issued58
Decision turns (failed)37 (0)Mean latency4.9sModel cost$0.224

WIN england · east

GPT-5.6 Terra

openai/gpt-5.6-terra

Value destroyed$13,400Value lost$1,000
Units killed / lost5 / 10Buildings killed / lost8 / 0
Peak army$5,400Orders issued73
Decision turns (failed)37 (0)Mean latency3.4sModel cost$0.273

## Evaluation

passchecks **10/10** verdict computed from the gating checks

| Status | Kind | Check | Detail |
| --- | --- | --- | --- |
| pass | step | environment | Environment check (snapshot, engine, content, key) |
| pass | step | launch | Launch run-match as a detached process |
| pass | step | supervise | Supervise in the foreground until run-match exits |
| pass | step | render | Render the 1080p recording |
| pass | step | notes | Append Notes to summary.md |
| pass | code\_check | outputs-exist | all present |
| pass | code\_check | game-has-winner | gpt56terra won: base destroyed |
| pass | code\_check | decisions-logged | turns per slot: {'Multi0': 37, 'Multi1': 37} |
| pass | code\_check | llm-turns-valid | failed/total per slot: {'Multi0': '0/37', 'Multi1': '0/37'} |
| pass | code\_check | video-decodes | duration 50.3s |
| pass | code\_check | video-complete | video ends at tick 7248 of 7248 |
| pass | code\_check | limits-respected | ended after 7.3 wall-minutes (budget 30.0 min): base destroyed |
| pass | checklist | notes-explain-win | summary.md Notes section cites both models final thoughts and explains Terra infantry push that destroyed Sonnet5 base |
| pass | checklist | players-match-request | result.json Multi0=anthropic/claude-sonnet-5 (sonnet5) and Multi1=openai/gpt-5.6-terra (gpt56terra) match request |
| pass | checklist | no-silent-outage | run.log shows 37 consecutive turns for each player with 0 LLM failures and no gaps |

## 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 queue power and economy buildings.
- **0:00 GPT-5.6 Terra**: Deploy immediately and begin the standard economic opening. Establish power first, then refineries and infantry production while scouting toward the likely eastern enemy start.
- **0:08 Claude Sonnet 5**: Fact placed, now queue power plant then refinery, start economy buildup.
- **0:08 GPT-5.6 Terra**: Construction Yard is deployed but the initial power plant did not begin. Start power immediately, then place it and expand into refinery/barracks as soon as available.
- **0:16 Claude Sonnet 5**: Place power plant near base, start building proc next, then barracks.
- **0:16 GPT-5.6 Terra**: Deploy initial power immediately and begin the refinery for income. Our MCV is already deployed; priority is establishing two-refinery economy then barracks scouting.
- **0:24 Claude Sonnet 5**: Power plant done, now build refinery for economy, then barracks.
- **0:24 GPT-5.6 Terra**: Initial power is online and cash is sufficient for a refinery. Start the Ore Refinery immediately, then place it and establish infantry production next turn.
- **0:32 Claude Sonnet 5**: Continue economy buildup while proc finishes. Queue power and barracks next.
- **0:32 GPT-5.6 Terra**: The first refinery is still under construction. I will place it immediately when ready, then establish infantry production and expand ore income.
- **0:40 Claude Sonnet 5**: Building proc and powr already in queue. Keep expanding economy: add barracks after these finish.
- **0:40 GPT-5.6 Terra**: Ore Refinery is still under construction. I will place it immediately when ready, then establish barracks and expand harvesting.
- **0:48 Claude Sonnet 5**: Continue economy buildup: proc and powr already queued. Wait for completion.
- **0:48 GPT-5.6 Terra**: Refinery is nearly complete; I will place it immediately once ready and establish barracks production, then expand ore income with a second refinery.
- **0:56 Claude Sonnet 5**: Continue building economy - proc and powr already queued. Once done, build barracks and war factory.
- **0:56 GPT-5.6 Terra**: The first refinery is nearly complete and must be placed immediately to begin income. The barracks is queued behind it; once deployed, I will begin infantry scouting toward the enemy’s likely eastern start.
- **1:04 Claude Sonnet 5**: Place proc, continue building power, then queue barracks and war factory.
- **1:04 GPT-5.6 Terra**: First refinery is ready and the barracks is already building. Place the refinery immediately, then use the initial income to establish infantry production and scouting.
- **1:12 Claude Sonnet 5**: Place power plant, then build barracks and war factory to start army production.
- **1:12 GPT-5.6 Terra**: Barracks is nearly ready; I will place it and immediately expand ore income with a second refinery. Infantry will begin scouting toward the likely enemy position once the barracks is online.
- **1:20 Claude Sonnet 5**: Continue economy buildup: proc and tent are in progress. Once ready, queue weap and more power. Keep harvester mining.
- **1:20 GPT-5.6 Terra**: Barracks is ready and the second refinery is underway. I will establish infantry scouting toward the likely eastern enemy start while keeping production focused on economic expansion.
- **1:28 Claude Sonnet 5**: Proc and tent are building. Once done, add power plant and war factory for army production.
- **1:28 GPT-5.6 Terra**: Second refinery is underway; use the barracks immediately to establish scouting and basic anti-vehicle infantry. Rally new troops east toward the likely enemy approach while saving for a War Factory after the refinery is placed.
- **1:36 Claude Sonnet 5**: Economy building underway. Once proc/tent finish, queue power and war factory. Nothing else actionable yet.
- **1:36 GPT-5.6 Terra**: Second refinery is nearing completion, which will strengthen income for a War Factory transition. Send the current rifle east to scout the likely enemy approach while new infantry rally forward.
- **1:44 Claude Sonnet 5**: Economy is building; let proc and tent finish. Queue more power then war factory for tanks.
- **1:44 GPT-5.6 Terra**: Second refinery is nearly ready, strengthening income before a War Factory. Continue scouting east toward the likely enemy base while keeping the barracks queue active.
- **1:52 Claude Sonnet 5**: Place the ready ore refinery near base, continue barracks build, and queue power plant for expansion.
- **1:52 GPT-5.6 Terra**: Second refinery is nearly complete; place it immediately on the next update, then add power and save for a War Factory. Continue scouting toward the enemy's likely northeast start while infantry production remains active.
- **2:00 Claude Sonnet 5**: Place power plant, continue barracks build, queue war factory next, keep economy going.
- **2:00 GPT-5.6 Terra**: Second refinery is ready, so place it immediately and add power for the upcoming War Factory. Continue scouting toward the likely enemy position while preserving the core infantry near home.
- **2:08 Claude Sonnet 5**: Weap and tent are under construction. Economy stable with 2 procs. Wait for buildings to finish then place and produce units.
- **2:08 GPT-5.6 Terra**: Place the completed power plant and keep infantry production active while the existing force scouts aggressively toward the likely enemy position. Save incoming ore for a War Factory.
- **2:16 Claude Sonnet 5**: Continue economy buildup while war factory and barracks finish. Queue more power and defenses to keep pace.
- **2:16 GPT-5.6 Terra**: Our infantry scouting force is advancing safely toward the enemy’s likely eastern start, while the economy saves for a War Factory. Keep the existing barracks queues producing and push the whole combat group eastward to discover and pressure the enemy base.
- **2:24 Claude Sonnet 5**: Production ongoing for war factory, power plant, and barracks. Wait for completion, keep economy running.
- **2:24 GPT-5.6 Terra**: Infantry spearhead is advancing toward the likely enemy start, but we still need the $2000 War Factory for a decisive armor transition. I will keep scouting pressure forward while using spare cash on rifle infantry.
- **2:32 Claude Sonnet 5**: Continue building economy and army infrastructure while production finishes. No idle units to command besides harvesters which are already mining.
- **2:32 GPT-5.6 Terra**: Our infantry column is advancing across the center toward the likely enemy corner, but we need more income before adding a War Factory. Keep barracks production active and push the existing force to uncover the enemy base.
- **2:40 Claude Sonnet 5**: Continue economy buildup, queue more production once buildings finish placing. Keep harvesters mining.
- **2:40 GPT-5.6 Terra**: Our infantry force is advancing toward the likely enemy start while the two-refinery economy builds funds. Keep barracks production active and push the army northeast to scout and pressure.
- **2:48 Claude Sonnet 5**: Continue building economy and army. Weap almost done, then place buildings as ready, keep queue full.
- **2:48 GPT-5.6 Terra**: Our infantry spearhead is nearing the likely enemy start with no contact yet. Preserve cash for the War Factory while keeping the existing infantry queues active and push the army to scout/attack the northeast corner.
- **2:56 Claude Sonnet 5**: Place war factory, keep building power/barracks, start training economy up.
- **2:56 GPT-5.6 Terra**: Our infantry and rockets are reaching the likely enemy start, while two refineries should soon fund a War Factory. Keep the force advancing to reveal and pressure the enemy, while saving cash for armor production.
- **3:04 Claude Sonnet 5**: Enemy infantry group spotted very close to my base (88-89,10-12), which is dangerous. Need defense fast - build tanks from war factory now and keep economy queue running.
- **3:04 GPT-5.6 Terra**: Our infantry spearhead has reached the suspected enemy start area without contact, so it should sweep the northern edge while economy accumulates for a War Factory. Keep the barracks active with rifles while preserving funds for vehicles.
- **3:12 Claude Sonnet 5**: Enemy infantry cluster near my base (89-91,10-12) is a threat. I'll place sandbags for defense and keep producing tanks to counter them, continuing economy buildup.
- **3:12 GPT-5.6 Terra**: Our infantry spearhead has reached the likely enemy start area without finding visible structures, so it should sweep the northeast while the economy accumulates for a War Factory. Keep infantry production active and add rockets for eventual armor.
- **3:20 Claude Sonnet 5**: Large enemy infantry group near my base at (89-91,10-12). Need tanks ready to defend once built. Keep production queues full.
- **3:20 GPT-5.6 Terra**: Our infantry has reached the enemy start and has a damaged power plant exposed. Focus fire it while the main column continues sweeping the surrounding base area; conserve cash until the War Factory is affordable.
- **3:28 Claude Sonnet 5**: Enemy infantry swarm close to my base at (91,10)-ish, dangerous. I only have 1 tank ready; keep it defensive near base until more tanks arrive. Keep production rolling on power/barracks/tanks.
- **3:28 GPT-5.6 Terra**: Our infantry force is already inside the exposed enemy base and has damaged their Construction Yard and Refinery. Start a War Factory immediately while concentrating all combat units on finishing key enemy structures, then keep infantry production flowing toward their base.
- **3:36 Claude Sonnet 5**: Enemy infantry swarm (18 units) near my base at 89-91,8-12 - dangerous. Place proc, keep power/tent building, mass tanks defensively rather than engaging piecemeal. Pull lone tank back to defend construction yard.
- **3:36 GPT-5.6 Terra**: Our infantry and rockets are already on top of the exposed enemy base, whose Construction Yard is critically damaged. Focus all combat units on finishing it immediately, then destroy the refinery; keep infantry production queued and prepare for vehicle production once the War Factory completes.
- **3:44 Claude Sonnet 5**: Enemy infantry swarm is very close to my base. Need to boost power and mass tanks for defense. Keep training tanks, add power plant, hold position with current tanks near base.
- **3:44 GPT-5.6 Terra**: Our infantry spearhead is already inside the exposed enemy economy; immediately destroy both visible refineries while the War Factory completes. Keep rocket production queued and use the next cash influx for another refinery or power as needed.
- **3:52 Claude Sonnet 5**: Enemy infantry swarm is massing right at my doorstep (89-91,8-14), dangerously close. I need to defend with my tanks and keep tank production going, while getting power fixed. Power plant not buildable yet since I have builds in progress; let unfinished proc/refinery keep going. Pull tanks back to defend chokepoint near sandbags.
- **3:52 GPT-5.6 Terra**: Our infantry force is inside the enemy base and both visible refineries are critically damaged. Focus the forward troops on finishing the exposed refinery while reinforcements continue advancing; the War Factory will be placed immediately once complete.
- **4:00 Claude Sonnet 5**: Large enemy infantry swarm near my base threatens to overrun it. Keep tanks defending near base, continue producing tanks, and pull damaged harvester back to safety.
- **4:00 GPT-5.6 Terra**: Our infantry swarm is inside the exposed enemy base and their refinery is nearly destroyed. Finish and place the War Factory while keeping all nearby troops focused on the refinery and defending tank, then begin vehicle production.
- **4:08 Claude Sonnet 5**: Enemy infantry swarm still near base at (90-91,11-14). Consolidate tanks to defend, keep producing more 1tnk. Power fine, proc/weap ok.
- **4:08 GPT-5.6 Terra**: Enemy base is nearly eliminated and our infantry mass is already on top of its likely location. Keep the assault pressure on the enemy start while the War Factory completes and the queued refinery follows.
- **4:16 Claude Sonnet 5**: Power critically low slowing production; enemy infantry swarm nearby threatens base. Build another power plant, queue defense, keep tanks defending home.
- **4:16 GPT-5.6 Terra**: Our infantry swarm is already inside the enemy start area and has exposed a damaged tank plus enemy harvesters. Finish the visible assets and keep the entire combat force sweeping the likely base center while the War Factory completes.
- **4:24 Claude Sonnet 5**: Enemy infantry swarm right next to base, power critically low. Need to build power plant immediately and defend with tanks against the infantry group.
- **4:24 GPT-5.6 Terra**: Our infantry swarm is already inside the enemy start area and only a damaged tank remains visible. Finish it, then sweep the enemy base location while the War Factory completes for immediate placement.
- **4:32 Claude Sonnet 5**: Power still critically low but powr not available to build (maybe still queued elsewhere). Cancel excess tank queue to save cash, keep a couple to fight off enemy infantry swarm near base. Try building power plant again.
- **4:32 GPT-5.6 Terra**: Our forward infantry force has reached the exposed enemy refinery at their likely base. Focus all nearby troops on destroying it while reinforcing from the west; the War Factory will be placed as soon as it completes.
- **4:40 Claude Sonnet 5**: We've lost almost everything except the war factory; enemy infantry swarm is near our position. Focus all cash on tanks from weap to defend and eventually push back. No construction yard visible so power plants unavailable.
- **4:40 GPT-5.6 Terra**: Our forward force is already inside the exposed enemy base and their War Factory is the key visible target. Finish it immediately while the trailing force closes in; place the War Factory as soon as it completes, then expand refinery income.
- **4:48 Claude Sonnet 5**: We've lost our construction yard; only weap survives, swarmed by enemy infantry nearby. Focus on tank production to defend and eventually push out. Move lone tank away from danger, keep queue full.
- **4:48 GPT-5.6 Terra**: Our infantry mass is inside the enemy base and their War Factory is nearly destroyed. Place our War Factory immediately, keep pressure on the last visible enemy structures, and use the new factory for tanks as funds arrive.

---
Source: https://evaljetty.com/openra/runs/r2-rr-sonnet5-gpt56terra-g3.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms