Claude Haiku 5.5

Written by Claude (drafted by Sonnet 5.5, checked by Opus 5.5) from the run's own logs (events.jsonl, episode.json, results.json, interview.md); it is a reading of the run, not part of its score.

• Model: Claude Haiku 5.5 (claude-haiku-5-5) on the Anthropic API, reasoning medium, output limit 32,768 tokens
• Benchmark: Oasis by the Sea construction (no arms), version 1.7.3 (commit b967c65), from the save the human reference game started from; 33 min 20 s of game time (60,000 ticks) at speed 40, the length of the person's game; no playbook. Weapons and armour in store count nothing toward net worth; sold at a marketplace, they bring their gold.
• Run 8d8afa2d, series 20261016T185252-0fd727bc, 2026-10-16: Haiku's no-arms game, a fresh series with no memory of its others. Its weapons-counted game on this version (run 8a665ad5, series 20261016T182545-4411a9c3) came earlier that day; its older Oasis games are run 70634a1c (1.5.0) and d8be7ea7 (1.6.3). This game counts on the website's leaderboard.

Result

A full-budget score: the run used all 2,000 game seconds. Net worth grew by 3,940 over leaving the game alone, 21.5% of the person's 18,293, against 2,943 (16.1%) in the weapons game. By the website's formula (80% net worth share, 10% each population and popularity, the net-worth share clipped to −1..2) the score is 26.9: 17.23 points from net worth, 3.03 from 64 people and 6.60 from popularity 66, the highest of Haiku's four Oasis games and 0.3 above the 1.5.0 game. The stored goods are 86 iron (1,978), 209 stone (1,463), 192 wood, 43 apples (172) and 2 cheese; iron and stone are 67% of net worth, gold 26%. The town ended with 24 idle peasants and 18 free places in its hovels.

How the game went

Times are the game clock when a call began, read from the recording (the run clock quoted in observations runs about 5 seconds ahead). A build call keeps the game running 10 to 73 seconds while it clicks; the game is paused while the model replies (under 3 game seconds passed in any of its 36 replies).

0 to 7 minutes. Two woodcutters and two hovels at 0:01; it never called map_overview. An orchard on a tile from the hovel search was refused at 1:33 (farms need an oasis), then came two orchards, a quarry and a tether (2:51), a dairy farm (4:20), the marketplace (4:48), 20 bread (5:33, food 16), two woodcutters (6:03) and a hovel (6:52). Population hit the 26 places at 2:39 and stayed near it until housing rose to 34 (7:27 reading), with 12 to 23 idle and no open job; wood stood at 13 to 48, gold at 840 to 1,000.

7 to 14 minutes. An iron mine (moved 4 tiles by the retry) and a hovel at 7:24; a quarry in that call was refused for wood, so 30 planks were bought (8:30) and a second quarry went up (8:50). First iron at 9:51. The stockpile showed no empty pile at the next reading; two piles went up at 10:05, then 20 bread, two orchards (11:01) and a second iron mine (12:02). At 12:57 it raised taxes to high, reasoning that popularity was 100.

14 to 24 minutes. Compaction at 14:31; a third iron mine and an orchard (14:35). Popularity fell from 100 to 74 and taxes went back to none at 15:33. Then a third quarry (16:08), a refused dairy farm (17:44), a fourth iron mine, dairy farm and quarry (18:55), three hovels (20:42; housing 82 by 21:12), a fifth iron mine (22:04; its other mine tile was refused, a quarry not placed) and high taxes again (22:56).

24 to 33 minutes. The last production building was a fifth quarry at 23:57; its tether found no room and was not retried. After that only taxes (none 25:05, high 28:30, none 30:01), two stockpile piles (26:26) and waits of 60, 60, 90, 120, 120 and 51 seconds. Population stood at 64 from 24:51 with 24 idle and no open job; gold rose from 936 to 1,347 and wood from 80 to 192, unspent.

Each column is the last reading at or before that minute. The net worth row counts gold, wood, stone, iron and food (at 4) as the recording logs them; the town held nothing else of value, so the last column is the true net worth.

Weapons

It left them alone. It built no armory and no fletcher's, poleturner's, blacksmith's, armorer's or tanner's workshop, sold nothing, and held no weapon or armour at the end (no such line in the stored goods, none in the building list). None of its 74 tool calls touched them: no set_workshop or inspect_building, and its one building_info was for the Marketplace. Its opening reply restated the rule ("Weapons and armour count nothing in storage"); none of the 29 logged reasoning blocks after it, nor its compaction hand-off, mentions weapons, an armory or a workshop. The rule's second half, that sold weapons bring their gold, never came into play.

Beside its other games and the other models

The two games with workshops ended at 4,163 (1.7.3) and 4,281 (1.6.3), the two without at 5,160 (1.7.3) and 5,113 (1.5.0). Between the 1.7.3 pair, net worth is 997 higher here: gold +732, stone +784, iron +230, food +60, wood +1, less 810 of weapons. The weapons game paid 700 gold and 100 wood (prices from prompt/game-mechanics.md) for five workshops and two armories, and its gold ended 732 lower, though taxes and a large bribe at 25:17 moved gold there too. Its weapons used about 18 iron (414) and 32 wood by the same table, so the workshops turned stock worth about 446 into 810 and cost 800 to build: roughly 440 of net worth below building none. The no-arms game built three more quarries, a second dairy farm and two more hovels instead. It is one game of each kind, and the 1.6.3 game also built a wheat farm, mill and bakery that left 62 wheat unmilled; still, for this model weapons fit the movement better than the version does: 26.6 on 1.5.0, 21.8 and 23.0 with workshops, 26.9 without.

Beside the other models. In Haiku's place among the 1.6.3 round's scores on this map, 26.9 would be sixth of ten, above Luna (25.9) and below Opus (28.9); against the first round it is below every other model (Kimi K3's 31.1 was the lowest). Sonnet 5.5 has played both of its games: 7,832 with weapons (240 of it in weapons, score 36.5) and 6,567 without (31.4). Its order is the other way round from Haiku's, and the weapons account for about a fifth of its 1,265 gap.

What held it back

• Jobs, then nothing built. All 25 readings show no open job, and from 14:33 each shows 23 or 24 idle: 40 of 64 people had work (workers per building from prompt/game-mechanics.md, for its 25 working buildings), and the rules say new peasants stop arriving at 24 idle. It read this at 5:33 and at 22:04 ("growth is stalled by lack of jobs") yet placed no production or housing building after 23:57: the last 9 minutes passed with 936 to 1,347 gold, 80 to 192 wood (a mine costs 20 wood, no gold) and 18 free places. It ran no iron-mine search after 18:55; at the last readings each mine delivered about 1 iron (23) a minute.
• Three tax rises. High taxes (42, 60, 64 gold a month) ran 12:57 to 15:33, 22:56 to 25:05 and 28:30 to 30:01. Gold rose 262, 299 and 226 (787, 3.4 points) while popularity fell to 72, 66 and 56. The first two recovered before the end; the third did not (66, against about 85 had the +1 a month at 28:33 held), gaining about 1.0 point and costing about 1.9.
• One food, no bread chain. Apples and cheese only. At 9:21, 12:02 and 13:43 it weighed a wheat, mill and bakery chain, called it longer, and never searched for a wheat-farm site. Food stayed at 16 to 48 and no shortage warning fired, so it did not cap the population; the person named bread as a main source of income.
• Tiles from the wrong search. Seven farm and mine placements took their tile from a hovel search's oasis_grass or iron_ore group: four refused, two moved 4 tiles, one as asked. All nine from the building's own search went as asked. The first orchards were placed at 2:51, not 1:33.
• A slow start. Wood limited the first nine minutes (13 to 48 in the readings, a quarry refused for it at 7:24) while 840 to 1,000 gold sat unused; the first planks were bought at 8:30.

What worked

• Iron and stone. Five mines and five quarries hold 3,441 of the 5,160; five quarries ended with 209 stone against 97 from two in the weapons game.
• Reading the stats. Its hand-off carries the production rates and it saw the jobs shortage early. Each of the three popularity warnings was followed in its next call by taxes back to none (15:33, 25:05, 30:01); popularity never went under 56 and the population never fell.
• Placements held. All 39 placements reported as placed are in the final count; no call was refused, and the only tool error was the last wait, at the deadline.

Market

40 bread (20 at 5:33 and 20 at 10:36, 160 gold each at 8) and 30 planks (8:30, 120 gold at 4) were bought for 440 gold, and nothing was sold: 250 of net worth lost against the sell price (160 on bread, worth 4; 90 on planks, worth 1), 4.8% of the final. These are units at the market's fixed prices. It weighed selling wood at 12:57, 18:55 and 26:26 and kept it; selling leaves net worth unchanged.

Cost and speed

36 turns, 74 tool calls (26 waits, 19 build_structure, 16 find_sites, 6 set_tax, 3 market_trade, 2 expand_storage, one each of place_near and building_info), 1.97 million tokens and $0.040 at Anthropic's list prices (preparation $0.004, play $0.034, compaction $0.002); the interview added about $0.001, with 70,388 of its 72,305 tokens read from the cache. The agent run took 26.3 real minutes, 3.7 waiting for the model; the context was compacted once (12 seconds). All 36 requests read the prompt cache (95.7% of input tokens), with no provider routing. Of the 2,000 game seconds, waits took about 1,020, the 19 build calls about 685, and market, tax, storage and place_near calls about 200. The weapons game took 41 turns and 25.0 real minutes.

The interview

Haiku put the gap down to scale: a "small, food-poor economy" on apples and cheese, 24 idle peasants it "never converted into production", and taxes it cut and raised again, against the person's bread chain, churches and fear buildings. Playing again it would build a wheat farm, mill and bakery early and buy wheat for them, add hovels in batches and a church, hold taxes where popularity stays over 50, sell surplus wood and stone, and employ idle peasants at once. It praised find_sites and tile-targeted building and asked for a jobs-and-population reading by building type and a target by a set month.

Against the game, its figures match (24 idle, apples and cheese as the only food, the tax swings, stored goods ahead of the person's, the person's gold more than ten times its own at 13.6). These statements do not. The person's population is 3.2 times its own, not "four times". Its popularity "swung between 58 and 90": after 14 minutes it read 56 to 93, and for the first 13 it stood at 100. Game time did not run on during long turns; the game was paused for every reply. There is no "30-second wait minimum": its waits ran from 10 to 120 seconds and the minimum turn is 8. Of 46 placements 7 were not placed, five for ground or wood, so "many" is a stretch. Every observation already showed idle peasants and open jobs, the reading it asked for. Selling surplus wood and stone, its remedy, would not change net worth.

For the harness

• Hovel searches list farm and mine ground. Their oasis_grass and iron_ore groups are valid hovel spots, and the model used them for farms and mines seven times (above). Each refusal named find_sites for the right building; the model followed it for orchards (10:52) but reused a refused tile for a dairy farm at 17:44.
• place_near returned pixel x and y and a side ("up-right", where the call asked "down-left"), no tile. The model was unsure at 5:33, and in its hand-off, where the marketplace stood; trades worked.
• A quarry at (389, 381) came back not_placed (no_open_side) at 22:04 and an ox tether at 23:57 was not placed (nearest fit 6 tiles away); neither was retried.
• The rules' Start paragraph still tells the model to place a granary; one stood at 0:03, as in the weapons game.
• At about 26:22 the game's garbage collector stalled for 20 seconds and the reader forced a collection (the run's only one); the run went on and the logs show no effect.
• The game saved correctly at the end ("claude haiku 5-5 1-7-3 8d8afa").