---
title: "GPT-5.6 Terra vs Gemini 3.8 Flash | OpenRA arena | Evals by Jetty"
url: https://evaljetty.com/openra/games/cup1-third-g2.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)
---

Pilot cup · cup1-third-g2

# GPT-5.6 Terra vs Gemini 3.8 Flash

GPT-5.6 Terra destroyed the enemy base after 5.9 game-minutes · 6.2 min wall clock

The recording stops at 3.3 of 5.9 game-minutes: this pilot game hit a since-fixed bridge bug (building sales were sent outside the lockstep order queue), so its replay drifts out of sync at the first sale. Results and stats come from the live game.

Pilot game (run locally, before the Jetty runs)
[Replay (.orarep)](https://evaljetty.com/openra/media/cup1-third-g2.orarep)
[Decision log](https://evaljetty.com/openra/runs/cup1-third-g2/decisions.jsonl)
[Runtime config](https://evaljetty.com/openra/runs/cup1-third-g2/runtime_config.json)

WIN ukraine · west

GPT-5.6 Terra

openai/gpt-5.6-terra

Value destroyed$8,600Value lost$2,400
Units killed / lost13 / 18Buildings killed / lost5 / 0
Peak army$3,400Orders issued60
Decision turns (failed)45 (0)Mean latency3.1sModel cost$0.311

LOSS ukraine · east

Gemini 3.8 Flash

google/gemini-3.8-flash

Value destroyed$2,400Value lost$8,600
Units killed / lost18 / 13Buildings killed / lost0 / 5
Peak army$1,800Orders issued30
Decision turns (failed)45 (0)Mean latency2.8sModel cost$0.147

## 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 GPT-5.6 Terra**: Deploy immediately and begin the standard Soviet economy opening with power.
- **0:00 Gemini 3.8 Flash**: Starting the match. Deploying MCV at home cell and queuing initial Power Plant.
- **0:08 GPT-5.6 Terra**: Construction Yard is deployed and the first power plant is underway. I will place it immediately when ready, then rush a refinery for income.
- **0:08 Gemini 3.8 Flash**: MCV is deployed. Need to start building power plant to kick off standard Soviet opening.
- **0:16 GPT-5.6 Terra**: Construction Yard is deployed and the opening power plant must be started immediately. I will establish power, then place it and rush the first refinery for income.
- **0:16 Gemini 3.8 Flash**: Power plant is ready. Place it immediately and start an Ore Refinery to get our economy and first harvester going.
- **0:24 GPT-5.6 Terra**: Construction Yard is deployed and the first power plant is ready. I will place it immediately, start a refinery for income, and begin basic infantry production as soon as infrastructure permits.
- **0:24 Gemini 3.8 Flash**: Power plant is up. Now queueing the first Ore Refinery (proc) to jumpstart income and get our first harvester.
- **0:32 GPT-5.6 Terra**: Power is established and cash is available; immediately start the first refinery to activate income, then build infantry for scouting and pressure.
- **0:32 Gemini 3.8 Flash**: Refinery is currently building at 23%. With plenty of cash ($4378), I need to wait for the refinery to finish, place it, then build a barracks and a second refinery.
- **0:40 GPT-5.6 Terra**: Ore Refinery is still constructing; preserve cash for immediate expansion into barracks and a second refinery once it completes.
- **0:40 Gemini 3.8 Flash**: Ore Refinery is halfway through construction. Waiting for it to finish so we can deploy our economy and get our first harvester.
- **0:48 GPT-5.6 Terra**: The first refinery is nearly complete and must be placed immediately to start income. I will follow with barracks production and begin infantry scouting toward the likely western enemy base.
- **0:48 Gemini 3.8 Flash**: Refinery is at 70% and will finish shortly. I'll pre-emptively queue barr once it's ready, but right now we wait the couple of seconds for proc to complete.
- **0:56 GPT-5.6 Terra**: The first refinery is still constructing and the barracks is queued behind it. I will place the refinery as soon as it finishes, then begin infantry scouting and sustain production.
- **0:56 Gemini 3.8 Flash**: Refinery is nearly finished; queue Barracks immediately to unlock military production and scouting. We will place the refinery once complete and follow up with a War Factory or second Refinery.
- **1:04 GPT-5.6 Terra**: The first refinery is almost complete and the barracks is queued behind it. I will place the refinery immediately, start the war factory path, and establish infantry production as soon as the barracks finishes.
- **1:04 Gemini 3.8 Flash**: Place the completed Ore Refinery to get our economy and first harvester started. Once placed and barracks completes, start training scouts and infantry while preparing to build a War Factory.
- **1:12 GPT-5.6 Terra**: The first refinery is ready while the barracks is constructing. Place it immediately to start income, then use the barracks for scouting infantry and expand into a second refinery/war factory.
- **1:12 Gemini 3.8 Flash**: Barracks is finishing up. We will prepare War Factory (weap) to unlock armor production and start producing basic infantry for scouting and defense.
- **1:20 GPT-5.6 Terra**: Barracks is nearly complete; immediately place it next turn and begin infantry scouting west. Economy is healthy with one refinery and surplus power, so keep the harvester mining while preparing a second refinery or war factory.
- **1:20 Gemini 3.8 Flash**: Barracks is ready to place. We will place the barracks, start training rifle infantry for scouting, and maintain war factory production to prepare for heavy tanks.
- **1:28 GPT-5.6 Terra**: Barracks is ready and the economy can support immediate scouting plus a second refinery. I will establish infantry scouting west while starting refinery #2, then transition to a War Factory.
- **1:28 Gemini 3.8 Flash**: Barracks is now complete, so infantry production is unlocked. War Factory is building; queue some riflemen to scout and rocket soldiers for defense.
- **1:36 GPT-5.6 Terra**: Second refinery is nearing completion, so I will immediately use the barracks for rifle scouts while saving for a War Factory. Scouts will head west toward the likely enemy start and reveal the map.
- **1:36 Gemini 3.8 Flash**: War Factory is progressing well and infantry is queued. Sending our rifle infantry to scout towards the enemy base at (95, 11) to map terrain and spot enemy build order.
- **1:44 GPT-5.6 Terra**: Second refinery is underway; keep expanding infantry while scouts push west toward the suspected enemy start. Save building queue for the War Factory immediately after the refinery is placed.
- **1:44 Gemini 3.8 Flash**: War Factory is halfway done. Let rifleman continue scouting towards likely enemy base at (95, 11). Keep infantry production running and prepare to place War Factory next turn.
- **1:52 GPT-5.6 Terra**: Second refinery is nearly complete; place it as soon as ready, then prioritize a War Factory and enough power to support it. Rifle scouts should keep pressing west toward the likely enemy base while infantry production continues.
- **1:52 Gemini 3.8 Flash**: Weap is at 66% completion. Continue scouting enemy base with the rifleman and queue up a couple more rocket soldiers to defend the home base while saving cash to place the War Factory.
- **2:00 GPT-5.6 Terra**: Second refinery is nearly ready, followed by the War Factory. Keep scouting west toward the likely enemy start while maintaining infantry production and sending the harvester to ore.
- **2:00 Gemini 3.8 Flash**: War factory will finish momentarily; preparing to place it as soon as ready and follow up with a power plant. Scouting enemy base at (95,11) with our rifleman while gathering rocket soldiers defensively.
- **2:08 GPT-5.6 Terra**: Second refinery is ready and must be placed immediately to expand income with a second harvester. Infantry scouting has not found the enemy yet, so keep the combat group advancing west toward the likely base while new infantry rallies forward.
- **2:08 Gemini 3.8 Flash**: War Factory is at 99% and will finish immediately; place it as soon as ready. Scout #135 continues towards the enemy base at (95, 11). Keep power building queued to support the new factory.
- **2:16 GPT-5.6 Terra**: Second refinery is operating and the War Factory is building. Keep infantry flowing and push the scouting force west toward the expected enemy base while harvesters mine.
- **2:16 Gemini 3.8 Flash**: War Factory is ready to place now. Place it immediately, queue another power plant or refinery once funds arrive from the harvester, and send a rocket soldier forward to scout towards the enemy start.
- **2:24 GPT-5.6 Terra**: War Factory is nearing completion while our infantry scouting line has advanced well toward the enemy’s likely western start. Keep the force pushing west to reveal and pressure the enemy base, while income funds the next production steps.
- **2:24 Gemini 3.8 Flash**: War Factory is complete, and a Power Plant is finishing soon. Cash is at $0, waiting for harvester #130 to dump ore so we can build a second harvester or refinery.
- **2:32 GPT-5.6 Terra**: War Factory is still constructing and cash is temporarily empty, while the scouting force is advancing toward the likely enemy start. Keep the army moving west to reveal and pressure the enemy, and ensure both harvesters remain mining.
- **2:32 Gemini 3.8 Flash**: Harvester is currently gathering ore at (17,6) and cash is at $0. Once the harvester unloads, cash will flow in to finish powr, then we need a second harvester and a Service Depot (fix) for Heavy Tanks.
- **2:40 GPT-5.6 Terra**: War Factory is nearly complete while our scouting infantry push has not yet found the enemy. Keep the army advancing toward the likely western base and rally future infantry forward; spend incoming ore on a Service Depot as soon as the factory is placed.
- **2:40 Gemini 3.8 Flash**: Harvester is currently unloading, which will fund our queued powr and harv. We'll group idle rocket soldiers slightly forward to guard the approach and keep scouting towards (95, 11).
- **2:48 GPT-5.6 Terra**: War Factory is nearly ready; place it immediately when complete and begin vehicle production as cash arrives. Infantry are already pressuring toward the enemy start, so keep their rally forward and eliminate visible rocket soldiers if encountered.
- **2:48 Gemini 3.8 Flash**: Power plant is ready to place. We need to place it, cancel the accidental second barracks to save cash, finish our second harvester, and prepare for fix (service depot) to unlock Heavy Tanks.
- **2:56 GPT-5.6 Terra**: War Factory is still constructing and our infantry column is closing on the exposed enemy refinery. Keep pressure on the west while saving ore for immediate vehicle production once the factory is placed.
- **2:56 Gemini 3.8 Flash**: Enemy rifle infantry are harassing near our refinery at (19,15). Our cash is at $0 waiting for harvester delivery, so let the pending e1 and harv complete to defend and stabilize income.
- **3:04 GPT-5.6 Terra**: War Factory is nearly ready while our infantry column is pressuring the exposed enemy refinery. Keep the advance aggressive and focus the refinery when units are in range; spend incoming ore immediately on vehicles once the factory is placed.
- **3:04 Gemini 3.8 Flash**: Harvester #130 is unloading/near refinery #129, and a second harvester is in production. Enemy infantry are probing outside our base at (19,15); once our rifleman finishes training and the harvester unloads cash, we will build base defenses and tanks to repel them.
- **3:12 GPT-5.6 Terra**: Our infantry is already at the exposed enemy refinery and should finish it immediately. The War Factory is ready to place, after which we will transition into nonstop vehicle production and continue the westward assault.
- **3:12 Gemini 3.8 Flash**: Enemy infantry ball is right outside my refinery at (19,16) and damaged it. The harvester at 47% will complete shortly and give me a second harvester, but I need basic infantry defense and need to protect the refinery.
- **3:20 GPT-5.6 Terra**: Our forward infantry has likely destroyed the exposed enemy refinery and is near their start. Place the completed War Factory immediately, keep infantry production flowing, and press all combat units through the enemy base area while adding another refinery.
- **3:20 Gemini 3.8 Flash**: Enemy infantry group is very close at (19,16) right outside our base. Our cash is $0 and our refinery seems destroyed (missing from building list!), but we have a harvester #130 mining. Need cash from #130 docking or surviving to rebuild economy, but without a refinery #130 can't dump ore! Wait, did refinery die? Yes, no proc in buildings list!
- **3:28 GPT-5.6 Terra**: Our forward infantry is on top of the exposed enemy War Factory and should finish it immediately. A refinery is building but power is currently low, so the next construction priority is a power plant followed by armor production.
- **3:28 Gemini 3.8 Flash**: Sold buildings gave us $400, but we need $1400 for a refinery so harvester can unload. With enemy infantry swarming our base, repair weap and use rifle infantry to hold off the attackers while we survive.
- **3:36 GPT-5.6 Terra**: Our forward infantry are at the enemy approach and the enemy base is just west around (12,16). Power is low while the refinery completes, so keep the assault pressure up and place the refinery immediately when ready before adding power.
- **3:36 Gemini 3.8 Flash**: Enemy infantry blob is attacking near War Factory (#153). We need Harvester #130 to unload ore to get funds, but we don't have an Ore Refinery right now (sold/destroyed). Without a refinery, harvester cannot unload, meaning we must build proc or save up.
- **3:44 GPT-5.6 Terra**: Our refinery is nearing completion but low power is slowing all production. Keep the remaining infantry advancing toward the known western enemy start while harvesters maintain income; immediately prioritize a power plant once funds arrive.
- **3:44 Gemini 3.8 Flash**: Our base is nearly wiped out with only ConYard and Power Plant remaining, cash at $400, and enemy infantry attacking nearby. We need immediate cash to rebuild an Ore Refinery so our harvester can unload; selling our Power Plant provides cash and spawns riflemen, while we can build a kennel or wait/sell to reach $1400. Wait, selling powr gives $150 (half of 300), total $550, still not enough for proc ($1400), but ConYard sell gives $2500 and an MCV/infantry, or we can build barracks with $500 if we sell powr. Let's sell powr, build barr ($500), train dogs/riflemen to survive, and defend base.
- **3:52 GPT-5.6 Terra**: The refinery is still building and power is low, so I will place it immediately when ready and follow with a power plant. Our scattered infantry should keep pressing west toward the suspected enemy base while harvesters continue mining.
- **3:52 Gemini 3.8 Flash**: We sold the power plant and now have $550, but no refinery is alive, so the harvester cannot unload unless we build a proc ($1480 which we can't afford right now) or rebuild powr -> barr or powr. Wait, can we produce powr? Yes, powr is $300. Let's start powr so we can unlock barr/proc.
- **4:00 GPT-5.6 Terra**: We are low power while the third refinery is nearing completion, so queue a power plant immediately behind it. Our scattered combat units should converge on the suspected enemy base and clear the visible technicians while infantry production continues.
- **4:00 Gemini 3.8 Flash**: Power plant is ready; placing it immediately will unlock barracks and refinery so we can rebuild. Harvester #130 is still operating, giving us future income, while our infantry finishes off the lone enemy rifleman.
- **4:08 GPT-5.6 Terra**: A refinery is nearly complete and the queued power plant will follow; low power is currently slowing production. Keep infantry pressure moving toward the likely enemy base while both harvesters continue mining.
- **4:08 Gemini 3.8 Flash**: Power plant is placed and active. With only $250 in cash and 1 harvester currently mining without a refinery, we desperately need to get a refinery or barracks running; wait for cash to build barr/proc.
- **4:16 GPT-5.6 Terra**: The second refinery is still building and a power plant is queued behind it; low power is slowing everything, so I will preserve income and keep infantry flowing. Our scattered scouts should continue probing west toward the enemy start while harvesters keep mining.
- **4:16 Gemini 3.8 Flash**: Our harvester #130 is mining ore at (21,8), but we only have $250 cash and need an Ore Refinery ($1400) or Barracks ($500). Wait for the harvester to unload, but since we don't have a refinery currently, wait—harvester #130 needs a refinery to unload! Wait, we don't have a proc, so where can it unload? It can't! But we have $250. Can we build a kennel for $200? Or save? Wait, without proc, harvester can't unload. Wait, did we lose our proc? Yes, lost 2 bldgs. If we have $250, we can't afford proc ($1400) or barr ($500). Wait! Can we sell power plant #179? A power plant costs $300, sells for $150 -> $400, still not enough for barr ($500). Wait, fact has repair ordered costing cash! Stop repairing fact immediately so we don't bleed our $250!
- **4:24 GPT-5.6 Terra**: Refinery construction is progressing but power is currently low, with a power plant queued immediately behind it. Our scattered infantry and rockets should continue pushing west toward the likely enemy base while new infantry reinforce forward.
- **4:24 Gemini 3.8 Flash**: Harvester #130 is alive but we have no refinery (proc) to unload into, so income is halted. Selling powr #179 gives $150, putting us at $400, but selling fact would give MCV ($2500 value if deployed/sold, or we lose fact). Actually, we have $250, kenn is $200! But kenn doesn't give income. If we sell powr #179 we get $150 -> $400. If we sell fact #122, does Soviet fact give MCV? In OpenRA selling fact yields an MCV! Then deploy MCV or sell MCV? Wait, selling ConYard in OpenRA yields 1 e1 + engineers/civilians or sells directly, it doesn't give MCV. Wait, can we afford barr ($500)? If we sell powr ($150), cash is $400. Let's see if we can sell damaged tecn/tecn2? No sell on units. Wait! What if we sell powr #179, and sell a wall? No. Let's check: why did harv stop? Harv cannot unload without proc. If we sell powr #179 ($150 back) we have $400. Wait, can we build kenn ($200) then sell it? Sells for $100 (loss).
- **4:32 GPT-5.6 Terra**: Our forward units should keep pressing west toward the likely enemy base while the refinery finishes. Power is currently low, so place the refinery immediately when ready and then prioritize the queued power plant.
- **4:32 Gemini 3.8 Flash**: We are stuck with only $250 and no refinery for the harvester to unload ore. Since we can't build a refinery ($1400) or barracks ($500) yet, our only building option under $250 is a kennel ($200) or we can sell the power plant #179 to get $150 (bringing us to $400) or sell #122 fact... wait! If we sell powr #179, we get $150, total $400. That's still not $500. But if we build kenn ($200), dogs cost $120. If we sell the fact, we get an MCV or cash? Selling fact gives 1 engineer and half cost ($1250) or an MCV? Wait, selling ConYard in OpenRA gives 50% cash and an engineer/minigunners, NOT an MCV. But wait, does our harvester have ore? It has nowhere to dump. Wait, can we sell fact to get $1250 + $250 = $1500, then we have no ConYard, we lose! Wait, why do we have $250? We can build kenn ($200), scout or attack with dogs? No, wait! Can we sell powr #179? Powr costs $300, selling gives $150 -> $400 cash. Wait, kenn is $200. Let's see if we can do anything with kenn or just build kennel first to get dogs to scout/kill.
- **4:40 GPT-5.6 Terra**: Low power is slowing the nearly complete third refinery, while two refineries and two harvesters are enough for now. Cancel the extra refinery to restore power production priority, consolidate the scattered combat force, and continue pushing west toward the likely enemy base.
- **4:40 Gemini 3.8 Flash**: Kennel is ready to place. We desperately need income, so harvester #130 must unload safely or continue harvesting until we can afford a Refinery ($1400). Repair our ConYard to keep it healthy while waiting for cash.
- **4:48 GPT-5.6 Terra**: Our forward infantry have exposed the enemy Construction Yard, which is the immediate win condition if it falls. Power Plant is underway to restore production; keep all combat units pressing directly onto the enemy base while harvesters continue mining.
- **4:48 Gemini 3.8 Flash**: Harvester is gathering ore; waiting on income to rebuild an Ore Refinery. An enemy rifle infantry is lurking near base; move technician away or keep fact repairing.
- **4:56 GPT-5.6 Terra**: Our assault is converging on the exposed enemy Construction Yard, while low power is slowing everything. Finish and place the power plant immediately when ready, then restore mining income and keep pressure on the enemy base.
- **4:56 Gemini 3.8 Flash**: Enemy infantry are attacking near our base; use our heavy harvester to crush them. We currently have no refinery and only $50, so we must eliminate threats first while looking for salvage or options.
- **5:04 GPT-5.6 Terra**: Enemy Construction Yard remains exposed and damaged at the known western start. Restore power immediately and keep every available combat unit driving directly onto the Construction Yard while ore unloads for the next build.
- **5:04 Gemini 3.8 Flash**: We are in dire straits with very little cash and only a Construction Yard, power plant, and kennel. The harvester is near the base; use it to crush the encroaching infantry (#175 rocket soldier and #174 rifleman) before it dies. We need cash from the harvester dump to rebuild our refinery.
- **5:12 GPT-5.6 Terra**: The enemy Construction Yard at (12,16) is badly damaged and appears to be the last visible enemy building. All available infantry should converge immediately to finish it while our refineries convert stored ore into cash.
- **5:12 Gemini 3.8 Flash**: We have no refinery and only $50, so harvester #130 cannot unload until we get cash or a refinery. We can sell Kennel #185 to get $100 (total $150), or sell Power Plant #179 to get $150, but we need $1400 for a refinery or $500 for barracks. Selling Kennel and Power Plant won't give enough for proc, but fact can be sold for $1000 + 5 engineers/soldiers or we can try to crush the enemy infantry #174 and #175 with the harvester right now.
- **5:20 GPT-5.6 Terra**: Enemy Construction Yard is critically damaged and our scattered force is already advancing across the map. Keep all combat units focused on finishing it while harvesters continue mining and infantry production completes.
- **5:20 Gemini 3.8 Flash**: Harvester #130 is nearby and must run over the enemy infantry threatening my damaged Construction Yard #122. Cash is critical ($50), need harvester to bring in ore or crush enemy infantry immediately.
- **5:28 GPT-5.6 Terra**: Enemy Construction Yard is critically damaged and our dispersed infantry are already converging on it. Maintain the direct attack to secure the immediate win while refinery income resumes spending capacity.
- **5:28 Gemini 3.8 Flash**: Construction Yard #122 is at critical 8% health and enemy infantry are right next to it. Harvester #130 is nearby at (21,8) and must immediately crush the attacking infantry while #122 continues repairing.
- **5:36 GPT-5.6 Terra**: The enemy Construction Yard was nearly destroyed and is currently out of sight; maintain pressure on their northwest start while expanding ore income. Start a third refinery and keep infantry production queued.
- **5:36 Gemini 3.8 Flash**: Our Construction Yard #122 was destroyed, leaving us with only a power plant, kennel, harvester, and captured/spawned technician. Our sole hope to rebuild or stay alive is to keep Harvester #130 mining safely and wait to see if we can scrape together funds or if we are effectively crippled.
- **5:44 GPT-5.6 Terra**: Our infantry and rockets are already converging on the exposed enemy start, where a power plant and nearly destroyed kennel remain visible. Keep pressure on that location while the third refinery completes to strengthen income.
- **5:44 Gemini 3.8 Flash**: Our base is almost completely overrun with only a power plant and a heavily damaged kennel remaining, plus enemy infantry attacking at (13,16). Harvester #130 is alive at (21,8) with minimal cash. We must keep the harvester away from the base area to survive.
- **5:52 GPT-5.6 Terra**: Enemy base is exposed at the northwest start and its remaining visible power plant is nearly destroyed. Keep all forces focused there while the refinery completes to sustain production.
- **5:52 Gemini 3.8 Flash**: Base has been virtually destroyed, only a dying power plant remains, while enemy infantry occupy our starting position. Harvester #130 is our only surviving unit; we must keep it safe and avoid dying to drag out survival or score if possible.

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Source: https://evaljetty.com/openra/games/cup1-third-g2.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms