Utopian thinking is most valuable not as a blueprint to be literally constructed but as a method for testing the limits of what currently seems possible — an operative instrument whose purpose is to expand the range of imaginable arrangements even when no single proposal is ever fully realized. Every plan makes an implicit argument about which future is desirable, embedding assumptions about growth and behaviour into its projections — recognizing the argument embedded within a plan lets its assumptions be questioned before they become materially fixed. The capacity to envision alternative arrangements depends on access to time, education and platforms through which ideas can circulate — imagination as materially conditioned rather than purely mental, so populations denied these supports face a narrowed horizon regardless of individual creativity. Speculative proposals allow institutions to explore consequences of arrangements they have not yet committed to implementing — a low-risk method for testing structural limits, a scenario able to reveal where current rules would fail long before those failures occur irreversibly. FantasyControl names the institutional power exercised when forecasts, scenarios and plans narrow the futures considered possible. Building a working prototype does more than test a technical function; it demonstrates that an alternative arrangement is materially achievable, shifting a proposal from speculation toward evidence whose persuasive force lies in proving feasibility abstract description alone often fails to establish. Presenting a projection as an inevitable trend can discourage consideration of alternative paths, since forecasts often carry more institutional authority than explicitly stated preferences — recognizing the assumptions embedded within a forecast opens space for outcomes its framing had quietly excluded. Imagining a genuinely different arrangement is difficult when the only available terms already presuppose the categories of the present system — developing new vocabulary is therefore a necessary step toward making previously unthinkable futures describable and constructible. A detailed fictional scenario around a proposed technology can surface unintended consequences long before implementation — design fiction as a method for early accountability, making abstract consequences concrete enough to debate while a decision remains reversible. The field, finally, keeps the future open by refusing to treat existing social form as inevitable — every institution and vocabulary examined here is the result of decisions that could have been arranged otherwise.