Almost every trader who starts keeping rules writes too many of them, in words too vague to enforce, and abandons the list inside a month. The failure is almost never discipline. It is drafting.
The test: could a stranger referee it?
Imagine somebody sitting behind you who knows nothing about your strategy. At the moment you are about to click, could they read the rule and say yes or no?
- "Trade with the trend" — they cannot. Which trend, on which timeframe, measured how? This is a preference.
- "No more than two trades before 12:00" — they can. It is a count and a clock.
- "Don't overtrade" — they cannot. Overtrading is a verdict you can only reach afterwards.
- "Stop for the day after two losers" — they can.
If a rule fails that test it will also fail at 09:40 on a Tuesday, because at 09:40 on a Tuesday you are the referee, and you are biased.
Four that survive contact
1. A hard trade count
Not because taking a fourth trade is inherently bad, but because the fourth trade is almost never the one you planned. It is the one the first three produced. A count is the cheapest possible guard against a bad state, and it is trivially referee-able.
2. A stopping condition, not a target
"Stop at two losses" works. "Stop at +2R" mostly does not, because nobody has ever struggled to stop while winning. Write the rule for the version of you that is behind.
3. One rule about the thing you actually do
Everybody has a signature leak: moving stops, chasing an entry after a miss, sizing up to recover, taking the setup that is almost the setup. You know which one yours is. Write that one in your own words, as specifically as you can bear: "I do not move a stop once the trade is live, for any reason."
4. Something you can only fail by not showing up
One rule that is purely about the ritual — writing the entry, closing the day, marking the levels the night before. It sounds like the least important one on the list and it is the one that keeps the other three alive, because it is the only one you can keep on a day when you do not trade at all.
Words to avoid
Try, generally, unless it's obvious, be careful, avoid. Every one of them is an escape hatch you wrote yourself, and you will find it at exactly the moment you go looking for one.
Rules also expire. The one that saved you in March may be irrelevant by September, and keeping a dead rule on the list teaches you that the list is negotiable. Retire it on purpose, in writing, on a calm day. Archive it rather than delete it, so the trades it judged keep the meaning of their verdict.
Then measure them
Four referee-able rules, checked before each trade for a fortnight, will give you a number most traders never obtain: how often you actually do what you decided to do. Almost nobody guesses it correctly. Nearly everybody is worse than they thought, and that is the only reason the number is worth having.