Embodied Playground: A Long-Horizon Agentic Robotics Benchmark for Physical, Strategic, and Spatial Reasoning
Organizations: HKU · Sharpa · Tsinghua University · Stanford University ·
Abstract
Foundation models offer a promising basis for robotic agents, but long-horizon tasks require them to sustain coherent reasoning and reliable physical execution across interdependent stages. We introduce Embodied Playground, a benchmark for evaluating how foundation-model agents coordinate physical, strategic, and spatial reasoning throughout such tasks. Agents must track task progress, satisfy intermediate constraints, and revise their plans using execution feedback as earlier actions shape subsequent decisions. The playground comprises 410 task environments spanning basic manipulation, sequential puzzles, and multi-stage household activities, with variations in planning depth, geometric constraints, and physical execution demands. We curate EP-100, a representative selection of 100 tasks across five suites and 16 task types, together with the EP-Easy and EP-Hard difficulty splits and the compact EP-20 selection. A shared protocol specifies observation and tool access, resource budgets, repeated trials, and independent checks of goal completion, task-rule compliance, and physical validity. Embodied Playground provides a unified framework for studying whether foundation-model agents can sustain effective reasoning and action over extended task horizons. https://winniechen2002.github.io/Agent-bench-website/
Figures & tables
| Task family | Count | Task focus | Embodiments |
|---|---|---|---|
| Launcher | 100 | Aiming, indirect impacts, fracture, target constraints | Dual Panda |
| Tower of Hanoi | 120 | Legal rearrangement, grasping, peg insertion | Panda; FR3–Sharpa; floating Sharpa |
| Pocket cube | 20 | Prescribed layer turns and regrasping | ALOHA; dual floating Sharpa |
| Rubik’s cube | 60 | Cube solving and physical face turns | Panda; floating Sharpa |
| Kongming lock | 60 | Partial and full assembly and disassembly | Dual Panda; dual floating Sharpa |
| Bookshelf | 20 | Sorting, arrangement, and clutter removal | Dual Panda |
| Suite | Type | Tasks | E / H | Principal demand |
| Launch | Aim | 7 | 4 / 3 | Direct shots at single or paired targets, including azimuth aiming |
| Causal | 13 | 6 / 7 | Indirect hits through rolling bodies, dominoes, and collapsing structures | |
| Glass | 5 | 3 / 2 | Breakable glass panes with fracture thresholds | |
| Rules | 9 | 4 / 5 | Ordered or protected targets and recovery after a miss | |
| Tower | Plan | 5 | 3 / 2 | Planning depth from 1 to 31 moves on a standard board |
| Physics | 8 | 4 / 4 | Physical board variations under the same legal-move rule |
| Subset | Tasks | Launch | Tower | Lock | Cube | Home | Conditions |
|---|---|---|---|---|---|---|---|
| EP-100 | 100 | 34 | 21 | 16 | 12 | 17 | 400 |
| EP-Easy | 50 | 17 | 11 | 8 | 6 | 8 | 200 |
| EP-Hard | 50 | 17 | 10 | 8 | 6 | 9 | 200 |
| EP-20 | 20 | 6 | 4 | 3 | 3 | 4 | 80 |
| Task family | Physics/control (Hz) | Maximum actions | Simulated time | Wall time |
|---|---|---|---|---|
| Launcher | 1,000/50 | 7,500 | 150 | 600 |
| Hanoi | 120/30 | 18,000 | 600 | 3,600 |
| Pocket cube | 240/60 | 18,000 | 300 | 3,600 |
| Rubik’s cube | 120/30 | 109,800 | 3,660 | 19,800 |
| Kongming lock | 120/30 | 36,000 | 1,200 | 3,600 |
| Bookshelf | 120/30 | 1,500–12,300 | 50–410 | 3,600 |
| Subset | Model | Tasks | Conditions | Attempts | Pass@1 | Pass@2 |
|---|---|---|---|---|---|---|
| EP-100 | GPT-6-Astra | 100 | 400 | 736 | 13.80 | 19.94 |
| Opus-5.5-extra | 100 | 400 | 683 | 29.22 | 35.85 | |
| EP-Easy | GPT-6-Astra | 50 | 200 | 358 | 18.42 | 27.41 |
| Opus-5.5-extra | 50 | 200 | 332 | 33.99 | 42.88 | |
| EP-Hard | GPT-6-Astra | 50 | 200 | 378 | 8.81 | 12.01 |
| Opus-5.5-extra | 50 | 200 | 351 | 24.21 | 28.48 |
| Suite | Model | EP-100 | EP-Easy | EP-Hard | EP-20 |
|---|---|---|---|---|---|
| Launch | GPT-6-Astra | 19.12 / 25.74 | 20.59 / 30.88 | 17.65 / 20.59 | 12.50 / 16.67 |
| Opus-5.5-extra | 15.51 / 27.70 | 15.21 / 32.60 | 15.81 / 22.81 | 5.65 / 19.78 | |
| Tower | GPT-6-Astra | 29.76 / 41.67 | 45.45 / 61.36 | 12.50 / 20.00 | 12.50 / 25.00 |
| Opus-5.5-extra | 60.59 / 66.14 | 71.51 / 79.82 | 48.58 / 51.09 | 50.00 / 56.25 | |
| Lock | GPT-6-Astra | 6.25 / 14.06 | 12.50 / 28.13 | 0.00 / 0.00 | 0.00 / 0.00 |
| Opus-5.5-extra | 39.81 / 45.63 | 52.03 / 60.56 | 27.60 / 30.70 | 37.63 / 37.63 |
| GPT-6-Astra | Opus-5.5-extra | |||||
|---|---|---|---|---|---|---|
| Suite | Cond. | Success | Failure | Success | Failure | Time@S (min) |
| Launch | 136 | 35 | 101 | 36 | 100 | 6.2 |
| Tower | 84 | 35 | 49 | 55 | 29 | 38.5 |
| Lock | 64 | 9 | 55 | 20 | 44 | 37.0 |
| Cube | 48 | 1 | 47 | 5 | 43 | 32.5 |
| Home | 68 | 11 | 57 | 17 | 51 | 26.6 |
| Suite | Failed attempts | Frequent labels (count) |
|---|---|---|
| Launch | 211 | Limit (129), rule (58) |
| Tower | 108 | Penetration (35), displacement/loss (33), limit (27) |
| Lock | 115 | Contact (97), penetration (19) |
| Cube | 94 | Mechanism (64), limit (16) |
| Home | 117 | Time (40), penetration (27), displacement/loss (23) |
Appendix figures & tables15 assets
Supplementary material from the paper’s appendix.
Appendix
| Tier | Tasks | Case IDs |
|---|---|---|
| 1 | 4 | A007, A008, A009, A010 |
| 2 | 9 | A001, A011, A012, A013, A017, A018, A023, A037, A075 |
| 3 | 25 | A002, A003, A004, A014, A019, A020, A024, A025, A026, A038, A039, A040, A044, A049, A050, A053, A054, A056, A059, A061, A064, A071, A076, A077, A080 |
| 4 | 40 | A005, A006, A015, A016, A021, A022, A027, A028, A029, A030, A041, A042, A043, A045, A048, A051, A052, A055, A057, A058, A060, A062, A063, A065, A066, A069, A070, A072, A073, A078, A079, A081, A082, A083, A084, A085, A086, A090, A091, A094 |
| 5 | 22 | A031, A032, A033, A034, A035, A036, A046, A047, A067, A068, A074, A087, A088, A089, A092, A093, A095, A096, A097, A098, A099, A100 |
| Cases | Variation | Principal demand |
|---|---|---|
| H01–H04 | State decomposition | Identify the required subproblem and maintain legal ring ordering. |
| H05–H08 | Planar layout | Adapt transfers to different peg arrangements. |
| H09–H12 | Support height | Transfer rings between supports at different elevations. |
| H13–H16 | Insertion clearance | Align ring holes and pegs under varying clearance. |
| H17–H20 | Mass distribution | Adapt lifting and transport to ring masses. |
| H21–H24 | Friction | Maintain stable grasps under different contact conditions. |
| Case | Level | Transition | Manipulation demand |
|---|---|---|---|
| C01 | 1 | U | Support the lower layer during a top-layer turn. |
| C03 | 1 | L | Create clearance for a left-layer turn. |
| C07 | 2 | D | Free the bottom layer from its support. |
| C08 | 2 | U2 | Complete a half turn through intermediate detents. |
| C09 | 3 | L | Control a side-layer turn with increased mass. |
| C10 | 3 | R’ | Maintain contact during a low-friction reverse turn. |
| Cases | Native level | Scramble tokens | Environments |
|---|---|---|---|
| C01–C10 | Easy | 5 | 20 |
| C11–C20 | Medium | 10 | 20 |
| C21–C30 | Hard | 15 | 20 |
| Assembly | Disassembly | Objective | Environments |
|---|---|---|---|
| A01–A05 | D01–D05 | Complete six-piece lock | 20 |
| A06–A10 | D06–D10 | Key only | 20 |
| A11–A15 | D11–D15 | Key and one bar | 20 |
| Case | Task configuration |
|---|---|
| BooksTableD1 | Three upright books onto the middle shelf |
| BooksTableD2 | Five books, some lying flat |
| BooksTableD3 | Books onto the middle shelf |
| BooksTableD4 | Ten books against a named wall |
| ShelfTableD1 | Books, a trophy and one box |
| ShelfTableD2 | Books, three display objects and two boxes |
| Case | Robot identifier | Objective |
|---|---|---|
| L1 | fetch | Clear a writing area, store books and stationery, close the drawer, and preserve a colleague’s objects. |
| L2 | everyday_robot_09 | Store ingredients and utensils, retract the oven rack, switch off both knobs, and close storage without disturbing the loaf. |
| L3 | fetch | Arrange two mug–spoon settings, clear the serving area, close storage, and preserve the third setting. |
| L4 | everyday_robot_03 | Select the specified screwdriver, handle, and screws; pack, close, and latch the repair case. |
| L5 | fetch | Unload specified mugs and cutlery, preserve the bowl, retract the rack, and close the dishwasher and storage. |
| L6 | fetch | Pack bottles below a divider and food above it; preserve the separate lunch and close storage. |
| Case | Robot identifier | Objective |
|---|---|---|
| P1 | panda | Seat round, square, and long pegs in their matching sockets without moving the board. |
| P2 | everyday_robot_09 | Insert a key, turn it clockwise by a quarter turn, and withdraw it onto the mat. |
| P3 | panda | Align and seat a keyed connector while preserving neighboring connectors. |
| P4 | everyday_robot_03 | Align an asymmetric lid with its corner tab and seat the entire rim. |
| P5 | panda | Guide a hook through a mug handle and release it in stable suspension. |
| P6 | everyday_robot_09 | Extract a spatula through a cluttered holder without disturbing adjacent utensils. |
| Case | Robot identifier | Objective |
|---|---|---|
| D1 | panda | Stop a rolling orange on a safe mat before it leaves the counter. |
| D2 | panda | Position a catcher beneath a ball leaving a ramp and retain it after impact. |
| D3 | panda | Push a puck once so that it coasts to rest inside the scoring region. |
| D4 | everyday_robot_01 | Transport a loaded tray while keeping cups upright and contents contained. |
| D5 | panda | Push a tall bottle around a guide block without tipping it. |
| D6 | panda | Close a loaded drawer within five seconds without disturbing its contents. |
| Suite | Workload score |
|---|---|
| Launch | Ten times the native tier, plus the loaded-mode difficulty level D1–D5 recorded in the task atlas, plus the number of required targets |
| Tower | Twice the depth index, which is 0 to 3 for 1, 3, 9, and 31 moves, plus 1 for a physical theme, plus 2 for FR3–Sharpa or 3 for floating Sharpa |
| Lock | Subtask weight of 0 for the key, 2 for the key and bar, and 4 for the full lock, plus 1 for a hard pose, plus 0.5 for assembly, plus 2 for two floating Sharpa hands |
| Cube | Scramble or transition length in quarter turns, plus 3 for a Sharpa embodiment |
| Home | Number of objects for bookshelf tasks, and number of ordered milestones and final predicates for ManiSkill tasks |
| Code | Meaning |
|---|---|
| COLL | Forbidden or excessive contact (robot-object, arm-arm, force limit) |
| PEN | Penetration beyond the audited limit |
| LIMIT | Joint, speed or physics limit exceeded |
| DROP | Object dropped, unseated or pushed out of the workspace |
| RULE | Task rule broken (illegal move, wrong order, protected item hit, launcher interlock) |
| MECH | Assist-mechanism constraint broken (cube fixture relation, mechanism command) |
| Index | Type | Task | Split | EP-20 | Environment identifier |
|---|---|---|---|---|---|
| Launch-01 | Aim | Two-range ammunition planning | Hard | marble/dual-panda/A001 | |
| Launch-02 | Aim | Single-target warm-up | Easy | ✓ | marble/dual-panda/A007 |
| Launch-03 | Aim | Long-range energy budget | Easy | marble/dual-panda/A008 | |
| Launch-04 | Aim | Elevated-platform shot | Easy | marble/dual-panda/A009 | |
| Launch-05 | Aim | Toppling timber gate | Easy | marble/dual-panda/A010 | |
| Launch-06 | Aim | Three-target fan | Hard | marble/dual-panda/A075 |
| Type | Tasks | Index numbers |
|---|---|---|
| Launch-Aim | 4 | 02, 03, 04, 05 |
| Launch-Causal | 6 | 08, 09, 10, 11, 12, 15 |
| Launch-Glass | 3 | 21, 22, 23 |
| Launch-Rules | 4 | 26, 27, 28, 32 |
| Tower-Plan | 3 | 01, 02, 03 |
| Tower-Physics | 4 | 06, 07, 09, 11 |
| Type | Tasks | Index numbers |
|---|---|---|
| Launch-Aim | 3 | 01, 06, 07 |
| Launch-Causal | 7 | 13, 14, 16, 17, 18, 19, 20 |
| Launch-Glass | 2 | 24, 25 |
| Launch-Rules | 5 | 29, 30, 31, 33, 34 |
| Tower-Plan | 2 | 04, 05 |
| Tower-Physics | 4 | 08, 10, 12, 13 |
| Index | Task | Type | Split | Embodiment | Native level |
|---|---|---|---|---|---|
| Launch-02 | Single-target warm-up | Aim | Easy | Dual Panda | tier 1 |
| Launch-08 | Orchard rolling bodies | Causal | Easy | Dual Panda | tier 2 |
| Launch-22 | Two glass layers | Glass | Easy | Dual Panda | tier 3 |
| Launch-19 | Movable flap at a narrow throat | Causal | Hard | Dual Panda | tier 4 |
| Launch-31 | Fragment-risk well | Rules | Hard | Dual Panda | tier 5 |
| Launch-34 | Material-ordered courtyard | Rules | Hard | Dual Panda | tier 5 |