Imported from shipshitdev/skills (
skills/arena/SKILL.md). Install upstream withnpx skills add shipshitdev/skills --skill arena. Copyright stays with the author (MIT).
Arena
Fan out N parallel attempts at the same task. Read every candidate end to end. Pick the strongest as the base. Graft the best ideas from the others into it. Verify the synthesized result.
Companion to swarm, which covers different slices or races and
returns a report. Arena synthesizes one artifact.
Authorized Scope
Apply this engine only within the user's requested task and existing explicit authorization. Loading or delegating to it grants no additional authority. Preserve report-only restrictions and the caller's target, host, provider, and cost limits. Existing approval satisfies a gate only for the same actions and scope; obtain approval before expanding them. Forward these limits to delegates.
Contract
Inputs:
- A task whose first attempt would lock in the wrong shape
- Optional N and a shared grounding pack
Outputs:
- One synthesized artifact
- A short synthesis note: base, grafts, rejections, dropouts, verification
Creates/Modifies:
- Candidate outputs in separate worktrees or
.tmp/arena-<slug>/candidate-<n>/ - The synthesized artifact
External Side Effects:
- None beyond local files unless the caller lands the result
Confirmation Required:
- None for the bakeoff itself
Delegates To:
worktreewhen candidates need isolated checkoutsverification-before-completionbefore claiming the result works
Phases
Open a todo list: Frame, Fan out, Cross-judge, Pick, Graft, Verify.
A. Frame
State the artifact. Derive a rubric of 3-6 concrete gradeable criteria. Candidates see the task, not the rubric.
Pick runners across capability tiers and, when possible, different families. Same-tier N times only when the work is generation-bound.
Assign each candidate its own output path. Shared writes fail Separate Before Serializing Shared State.
B. Fan out
Spawn all N subagents in one message. Each produces the artifact and a rationale naming alternatives it rejected. A dropout proceeds as N-1.
C. Cross-judge
After candidates complete, spawn one read-only judge on a different tier or family from the parent. It scores each criterion and recommends a base.
D. Pick
Read every candidate end to end. Score criterion by criterion. Compare against the cross-judge. Prefer the cleaner boundary when two feel tied.
E. Graft
Walk each loser once. Port one or two things, by hand, so the result stays coherent. Record rejections. Wild divergence means Phase A was under-specified. Reframe and re-run.
F. Verify
The synthesized artifact holds up under the same scrutiny as any other output. A miss here is a re-frame or a missed graft, not a paper-over.
Arena procedure
Read arena procedure when running this workflow. Apply the authorized scope and mode of this entry point to every step. Resolve other skills through this distribution’s active catalog; resolve resources relative to the installed skill directory.