A guardrail is a constraint that operates without requiring willpower at the moment of highest emotional activation. The design principle is critical: guardrails must be pre-committed and non-negotiable. A max daily loss rule that you override under emotional pressure is not a guardrail — it is a suggestion.
**Max daily loss.** Set as a dollar amount or percentage of equity. When hit, the session ends. No override, no 'one more trade.' This is the most effective single guardrail for limiting tilt damage. For most traders, 90% of catastrophic sessions would have been contained if the session had simply ended at a predefined loss limit.
**Cooldown timer.** After any stop loss above a size threshold, mandatory 15-minute no-entry window. Log the urge to trade during the cooldown — not to suppress it, but to make it visible and data-rich for later review.
**Size reduction trigger.** After two consecutive losing trades, position size reduces automatically by 50% for the next three trades. This limits damage even when tilt has not fully resolved.
**Session time limit.** Hard stop at a predefined end time regardless of session P&L. This prevents session extension on losing days — a common tilt pattern.