A Unified Arena for LLM Agents across Diverse Eurogame
Organizations: Alibaba Group · Nanjing University · National University of Singapore · Department of Computer Science, University of North Carolina at Chapel Hill ·
Abstract
Interactive environments offer a practical way to evaluate large language model (LLM) agents, and competitive games extend this evaluation to decisions shaped by competing goals and other agents' choices. Yet existing evaluations confined to individual games or execution frameworks leave unclear which competitive advantages persist across settings. We introduce DECE (Diverse Eurogame Competitive Environments), a unified arena spanning ten Eurogames with shared interfaces and evaluation protocols. These games combine lasting strategic commitments, competition over shared resources, and multiple routes to victory. Our primary study evaluates 12 model-harness configurations, spanning nine models and four execution harnesses, in 480 three-player matches across ten games. The main and supplementary studies comprise 1,032 completed matches in total. These comparisons reveal broad cross-game ranking agreement alongside game-specific strengths. Matched studies show that the same model can perform differently across execution harnesses, adding another source of variation to these profiles. These performance advantages do not consistently translate into better token or cost efficiency, making resource use an additional consideration when comparing configurations. Together, the findings support evaluating complete agent configurations by both their competitive performance across games and the resources needed to achieve it.
Figures & tables
| Benchmark | Game scope | Interaction | Main decision demands | Evaluation focus |
|---|---|---|---|---|
| GameBench ( 2024 ) | 9 board, card and social games | Players or teams | Spatial tactics, deck building and social inference | Competitive play; scaffold comparisons |
| MindGames ( 2026 ) | 4 strategic and social games | 2–6 players; rivals or teams | Opponent inference, signaling, trust and deception | Social reasoning; arena validity |
| FinBoardBench ( 2026b ) | Cashflow, Acquire, Monopoly | 4-player competition | Cash flow, investment, mergers and negotiation | Financial decision analysis |
| PTCG-Bench ( 2026 ) | Pokémon TCG; 5 decks | 2-player competition | Card combinations, resource recovery and action order | Self-evolution; harness and cost analysis |
| From Code to Play ( 2024 ) | 12 TAG tabletop games | 2–4-player tournaments | Deck building, drafting and tactical card play | Generate evaluators for search agents |
| LudoBench ( 2026 ) | 5 strategy board games | Fixed states | Perception, rule integration and local optimization | Fixed-state question answering |
| Group | Game | Tier | Players | Distinctive strategic demand |
| Capacity | Splendor | 2–4 | Shared-market timing; engine investment | |
| Century: Spice Road | 2–5 | Resource conversion; hand cycling | ||
| Wingspan | 2–5 | Tableau synergies; activation order | ||
| Spatial | Azul | 2–4 | Drafting; spatial scoring; denial | |
| Harmonies | 2–4 | Three-dimensional pattern construction | ||
| Carcassonne | 2–5 | Shared topology; follower commitment |
| Capacity | Space | Coordination | ||||||||||
| Participant | ID | SP | CE | WI | AZ | HA | CA | 7W | BU | BR | AN | Mean |
| GPT-5.6-Sol / Codex | 1 | 66.7 | 66.7 | 83.3 | 66.7 | 75.0 | 66.7 | 66.7 | 70.8 | 95.8 | 95.8 | 75.4 |
| GPT-5.6-Sol / OpenCode | 2 | 54.2 | 87.5 | 75.0 | 66.7 | 79.2 | 81.2 | 75.0 | 87.5 | 66.7 | 83.3 | 75.6 |
| GPT-5.6-Terra / Codex | 3 | 37.5 | 70.8 | 45.8 | 33.3 | 37.5 | 39.6 | 41.7 | 41.7 | 79.2 | 75.0 | 50.2 |
| GPT-5.6-Luna / Codex | 4 | 20.8 | 12.5 | 16.7 | 37.5 | 37.5 | 29.2 | 25.0 | 41.7 | 33.3 | 41.7 | 29.6 |
| DSV4-Pro / DSH | 5 | 58.3 | 58.3 | 62.5 | 58.3 | 58.3 | 66.7 | 66.7 | 58.3 | 58.3 | 58.3 | 60.4 |
| Public spatial ( ) | Other games ( ) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | Harness A | AZ | HA | CA | BU | SP | CE | WI | 7W | BR | AN |
| Qwen3.8-Max | Qwen Code | ||||||||||
| GPT-5.6-Sol | Codex | ||||||||||
| DSV4-Pro | DSH | ||||||||||
Appendix figures & tables27 assets
Supplementary material from the paper’s appendix.
Appendix
| Game | Rules edition | Configuration scope |
|---|---|---|
| Splendor | Classic base rules | Developments, reservations, and nobles. |
| Century: Spice Road | Plan B base rules (2017) | Merchant hands public in DECE. |
| Wingspan | Stonemaier base English rules | Base English set; green goal board. |
| Azul | Next Move base rules (2018) | Colored-wall variant. |
| Harmonies | Libellud base rules (2024) | Board A; nature spirits disabled. |
| Carcassonne | Base rules with farmers | Base game with farmers. |
| ID | Recorded model string | Harness | Effort |
|---|---|---|---|
| 1 | gpt-5.6-sol | Codex | xhigh |
| 2 | openai/gpt-5.6-sol | OpenCode | xhigh |
| 3 | gpt-5.6-terra | Codex | xhigh |
| 4 | gpt-5.6-luna | Codex | xhigh |
| 5 | deepseek-v4-pro-0813 | DSH | max |
| 6 | deepseek-v4-pro-0813 | OpenCode | max |
| Game | EC | SP | AS | OC | HI | SC |
|---|---|---|---|---|---|---|
| Splendor | 2 | 0 | 1 | 1 | 1 | 1 |
| Century: Spice Road | 2 | 0 | 2 | 1 | 0 | 1 |
| Wingspan | 2 | 0 | 2 | 1 | 2 | 2 |
| Azul | 0 | 2 | 1 | 2 | 0 | 2 |
| Harmonies | 0 | 2 | 1 | 1 | 0 | 2 |
| Carcassonne | 0 | 2 | 1 | 2 | 0 | 2 |
| Game | Matches | : median [IQR] | Engine turns | |
|---|---|---|---|---|
| Splendor | 48 | 81 [77.2, 84] | 81 | 27 |
| Century | 48 | 129 [119.2, 135] | 129 | 43 |
| Wingspan | 48 | 370 [357.8, 411.2] | 370 | 123.3 |
| Azul | 48 | 70 [67.8, 72.2] | 70 | 23.3 |
| Harmonies | 48 | 166.5 [158.8, 171.2] | 166.5 | 55.5 |
| Carcassonne | 48 | 142 [142, 142] | 142 | 47.3 |
| Game | 3p matches | Appear./config. | Each seat | 2p matches | 4p matches |
|---|---|---|---|---|---|
| Splendor | 48 | 12 | 4 | 72 | 36 |
| Century | 48 | 12 | 4 | – | – |
| Wingspan | 48 | 12 | 4 | – | – |
| Azul | 48 | 12 | 4 | – | – |
| Harmonies | 48 | 12 | 4 | – | – |
| Carcassonne | 48 | 12 | 4 | – | – |
| Configuration | ID | SP | CE | WI | AZ | HA | CA | 7W | BU | BR | AN |
|---|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 1 | 1622 | 1686 | 1811 | 1609 | 1821 | 1634 | 1634 | 1699 | 2068 | 2143 |
| GPT-5.6-Sol / OpenCode | 2 | 1552 | 1908 | 1728 | 1629 | 1888 | 1789 | 1695 | 1884 | 1673 | 1902 |
| GPT-5.6-Terra / Codex | 3 | 1419 | 1746 | 1511 | 1385 | 1328 | 1385 | 1445 | 1435 | 1794 | 1752 |
| GPT-5.6-Luna / Codex | 4 | 1275 | 1105 | 1170 | 1414 | 1329 | 1327 | 1297 | 1413 | 1328 | 1432 |
| DSV4-Pro / DSH | 5 | 1567 | 1646 | 1603 | 1561 | 1561 | 1641 | 1620 | 1590 | 1591 | 1614 |
| DSV4-Pro / OpenCode | 6 | 1550 | 1613 | 1378 | 1478 | 1660 | 1477 | 1583 | 1598 | 1525 | 1605 |
| Configuration | Mean PWS (%) | 95% interval |
|---|---|---|
| GPT-5.6-Sol / OpenCode | 75.6 | [69.7, 81.3] |
| GPT-5.6-Sol / Codex | 75.4 | [68.9, 81.7] |
| Qwen3.8-Max / Qwen Code | 70.2 | [64.5, 75.7] |
| DSV4-Pro / DSH | 60.4 | [53.6, 67.0] |
| Qwen3.8-Max / OpenCode | 58.3 | [51.9, 64.7] |
| DSV4-Pro / OpenCode | 54.2 | [47.3, 60.8] |
| Game | LOEO | Order acc. | Split-half mean | Split 5–95% range |
|---|---|---|---|---|
| SP | 0.49 | 75.4% | 0.18 | [-0.07, 0.44] |
| CE | 0.72 | 86.2% | 0.58 | [0.38, 0.78] |
| WI | 0.72 | 86.2% | 0.55 | [0.33, 0.74] |
| AZ | 0.59 | 80.6% | 0.27 | [0.00, 0.53] |
| HA | 0.71 | 85.9% | 0.64 | [0.47, 0.80] |
| CA | 0.86 | 93.8% | 0.49 | [0.27, 0.71] |
| Configuration | SP | CE | WI | AZ | HA | CA | 7W | BU | BR | AN |
|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 2 | 4 | 2 | 3 | 4 | 4 | 2 | 3 | 1 | 1 |
| GPT-5.6-Sol / OpenCode | 5 | 1 | 3 | 2 | 2 | 2 | 1 | 1 | 3 | 2 |
| GPT-5.6-Terra / Codex | 10 | 3 | 6 | 11 | 10 | 7 | 8 | 8 | 2 | 4 |
| Qwen3.8-Max / Qwen Code | 1 | 2 | 1 | 1 | 1 | 1 | 9 | 2 | 6 | 8 |
| Qwen3.8-Max / OpenCode | 9 | 5 | 4 | 8 | 3 | 5 | 5 | 10 | 7 | 3 |
| DSV4-Pro / DSH | 4 | 6 | 5 | 4 | 6 | 3 | 3 | 5 | 4 | 5 |
| Descriptive check (Qwen3.8-Max throughout) | PWS difference (pp) |
|---|---|
| Public spatial: Qwen Code minus OpenCode | |
| Same contrast, omit Azul | |
| Same contrast, omit Harmonies | |
| Same contrast, omit Burgundy | |
| Same contrast, omit Carcassonne | |
| HI=2: Qwen Code minus OpenCode |
| ID | SP | CE | WI | AZ | HA |
|---|---|---|---|---|---|
| 1 | 66.7 [40.0, 90.9] | 66.7 [38.9, 90.0] | 83.3 [68.8, 95.8] | 66.7 [43.8, 87.5] | 75.0 [54.5, 92.9] |
| 2 | 54.2 [35.7, 73.1] | 87.5 [66.7, 100.0] | 75.0 [55.0, 92.9] | 66.7 [47.2, 85.0] | 79.2 [59.1, 95.8] |
| 3 | 37.5 [13.6, 62.5] | 70.8 [50.0, 88.9] | 45.8 [25.0, 68.8] | 33.3 [12.5, 56.2] | 37.5 [14.3, 62.5] |
| 4 | 20.8 [4.2, 40.9] | 12.5 [0.0, 25.0] | 16.7 [0.0, 37.5] | 37.5 [14.3, 62.5] | 37.5 [20.0, 55.0] |
| 5 | 58.3 [37.5, 78.1] | 58.3 [42.3, 75.0] | 62.5 [40.9, 83.3] | 58.3 [30.0, 83.3] | 58.3 [38.2, 78.6] |
| 6 | 58.3 [31.8, 85.0] | 50.0 [33.3, 66.7] | 37.5 [13.6, 62.5] | 45.8 [30.6, 60.0] | 62.5 [40.0, 83.3] |
| Token-usage coverage | ||||
|---|---|---|---|---|
| Configuration | ID | Decisions | Summary coverage | Combined coverage |
| GPT-5.6-Sol / Codex | 1 | 8,176 | 0/120 | 120/120 |
| GPT-5.6-Sol / OpenCode | 2 | 7,975 | 114/120 | 120/120 |
| GPT-5.6-Terra / Codex | 3 | 7,673 | 0/120 | 120/120 |
| GPT-5.6-Luna / Codex | 4 | 7,303 | 0/120 | 120/120 |
| DSV4-Pro / DSH | 5 | 7,656 | 114/120 | 120/120 |
| Nominal model | Uncached input | Cached input | Output |
|---|---|---|---|
| GPT-5.6-Sol | 4.0000 | 0.4000 | 20.0000 |
| GPT-5.6-Terra | 2.0000 | 0.2000 | 12.0000 |
| GPT-5.6-Luna | 0.2000 | 0.0200 | 1.2000 |
| DSV4-Flash | 0.4424 | 0.0442 | 1.3272 |
| DSV4-Pro | 1.3272 | 0.1327 | 3.9817 |
| GLM-5.2 | 1.1797 | 0.2949 | 4.1291 |
| Configuration | ID | SP | CE | WI | AZ | HA | CA | 7W | BU | BR | AN |
|---|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 1 | 4.95 | 10.29 | 38.90 | 3.73 | 12.06 | 12.71 | 3.84 | 19.19 | 40.53 | 37.20 |
| GPT-5.6-Sol / OpenCode | 2 | 3.87 | 9.64 | 34.18 | 3.33 | 11.74 | 11.93 | 2.85 | 19.89 | 16.83 | 34.14 |
| GPT-5.6-Terra / Codex | 3 | 2.31 | 6.26 | 17.29 | 2.37 | 5.98 | 6.40 | 2.01 | 10.89 | 25.07 | 20.63 |
| GPT-5.6-Luna / Codex | 4 | 0.42 | 0.61 | 1.48 | 0.25 | 0.63 | 0.62 | 0.26 | 1.12 | 2.00 | 1.85 |
| DSV4-Pro / DSH | 5 | 2.53 | 4.92 | 9.19 | 2.82 | 4.20 | 5.81 | 2.38 | 7.25 | 13.69 | 11.36 |
| DSV4-Pro / OpenCode | 6 | 1.79 | 4.74 | 13.64 | 2.18 | 4.60 | 8.57 | 1.71 | 12.42 | 22.07 | 23.50 |
| Configuration | PWS (%) | USD [95% interval] | Tokens (M) |
|---|---|---|---|
| GPT-5.6-Sol / Codex | 75.4 | 18.34 [17.83, 18.89] | 31.89 |
| GPT-5.6-Sol / OpenCode | 75.6 | 14.84 [14.38, 15.35] | 27.79 |
| GPT-5.6-Terra / Codex | 50.2 | 9.92 [9.63, 10.20] | 31.21 |
| GPT-5.6-Luna / Codex | 29.6 | 0.92 [0.89, 0.96] | 27.74 |
| DSV4-Pro / DSH | 60.4 | 6.42 [6.21, 6.62] | 32.76 |
| DSV4-Pro / OpenCode | 54.2 | 9.52 [8.81, 10.28] | 61.06 |
| Configuration | ID | Games | Sp | Ce | Wi | Az | Ha | Ca | 7W | Bu | Br | AN |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 1 | 5/10 | 44.3 | 12.2 | 63.6 | 29.6 | 26.3 | 19.8 | 18.3 | 51.0 | 90.3 | 94.0 |
| GPT-5.6-Sol / OpenCode | 2 | 9/10 | 22.4 | 83.8 | 54.5 | 51.7 | 64.5 | 88.7 | 55.5 | 90.7 | 69.8 | 83.5 |
| GPT-5.6-Terra / Codex | 3 | 3/10 | 4.7 | 81.2 | 16.0 | 3.7 | 0.7 | 2.5 | 7.7 | 7.2 | 74.5 | 85.6 |
| GPT-5.6-Luna / Codex | 4 | 10/10 | 99.8 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 60.4 | 100.0 |
| DSV4-Pro / DSH | 5 | 10/10 | 37.0 | 71.4 | 81.5 | 42.6 | 71.5 | 98.7 | 49.6 | 76.5 | 93.1 | 92.0 |
| DSV4-Pro / OpenCode | 6 | 5/10 | 63.0 | 70.1 | 3.7 | 14.6 | 83.1 | 6.2 | 65.7 | 44.8 | 6.7 | 16.3 |
| Configuration | ID | USD | Tokens | SP | CE | WI | AZ | HA | CA | 7W | BU | BR | AN |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 1 | 5 | 8 | 70.4 | 60.6 | 79.5 | 42.3 | 93.7 | 90.0 | 31.1 | 97.3 | 96.2 | 98.8 |
| GPT-5.6-Sol / OpenCode | 2 | 9 | 9 | 99.9 | 92.7 | 62.2 | 98.2 | 73.0 | 81.6 | 99.2 | 88.7 | 99.4 | 17.4 |
| GPT-5.6-Terra / Codex | 3 | 3 | 2 | 7.7 | 11.9 | 31.2 | 0.4 | 67.9 | 59.9 | 1.1 | 26.1 | 49.5 | 16.5 |
| GPT-5.6-Luna / Codex | 4 | 10 | 3 | 0.1 | 0.1 | 31.6 | 0.9 | 69.1 | 80.6 | 0.0 | 2.3 | 1.3 | 77.5 |
| DSV4-Pro / DSH | 5 | 10 | 2 | 15.9 | 1.2 | 92.3 | 16.9 | 31.0 | 5.7 | 16.7 | 1.8 | 24.0 | 47.3 |
| DSV4-Pro / OpenCode | 6 | 5 | 0 | 21.3 | 0.0 | 0.1 | 0.5 | 6.4 | 0.5 | 13.9 | 1.5 | 0.0 | 0.0 |
| Configuration | ID | SP 2p | SP 4p | 7W 4p | BR 2p | BR 4p |
|---|---|---|---|---|---|---|
| GPT-5.6-Sol / Codex | 1 | 50.0 | 55.6 | 77.8 | 100.0 | 91.7 |
| GPT-5.6-Sol / OpenCode | 2 | 58.3 | 52.8 | 58.3 | 83.3 | 66.7 |
| GPT-5.6-Terra / Codex | 3 | 58.3 | 29.2 | 56.9 | 91.7 | 77.8 |
| GPT-5.6-Luna / Codex | 4 | 16.7 | 13.9 | 36.1 | 29.2 | 44.4 |
| DSV4-Pro / DSH | 5 | 66.7 | 69.4 | 52.8 | 29.2 | 75.0 |
| DSV4-Pro / OpenCode | 6 | 58.3 | 47.2 | 62.5 | 50.0 | 38.9 |
| Game | Focal model | OpenCode | Qwen Code | PWS [95% CI] |
|---|---|---|---|---|
| Splendor | DSV4-Flash | 50.0 | 55.6 | |
| Splendor | Qwen3.8-Flash | 38.9 | 55.6 | |
| 7 Wonders | DSV4-Flash | 66.7 | 61.1 | |
| 7 Wonders | Qwen3.8-Flash | 27.8 | 72.2 | |
| Equal-game mean | DSV4-Flash | 58.3 | 58.3 | |
| Equal-game mean | Qwen3.8-Flash | 33.3 | 63.9 |
| Focal model | Harness | PWS (%) | First | Second | Third |
|---|---|---|---|---|---|
| Qwen3.8-Flash | Qwen Code | 63.9 | 9 | 5 | 4 |
| DSV4-Flash | OpenCode | 58.3 | 7 | 7 | 4 |
| DSV4-Flash | Qwen Code | 58.3 | 6 | 9 | 3 |
| Qwen3.8-Flash | OpenCode | 33.3 | 3 | 6 | 9 |
| Game | Model | OpenCode | Qwen Code | [95% interval] | |
|---|---|---|---|---|---|
| Splendor | Qwen3.8-Flash | 25.0 | 33.3 | 3/1/2 | |
| Splendor | Qwen3.8-Max | 33.3 | 91.7 | 6/0/0 | |
| 7 Wonders | Qwen3.8-Flash | 16.7 | 33.3 | 3/1/2 | |
| 7 Wonders | Qwen3.8-Max | 75.0 | 83.3 | 1/4/1 |
LLM Agent Evaluation
Large language model agent evaluation measures whether tool-using systems complete tasks reliably, safely, and efficiently.
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