My teenager is on their phone constantly. What actually works to cut down screen time without a war?

Rules imposed with no input from the teen tend to produce more conflict, not less — the approaches that actually hold tend to involve them in setting them. 1. Separate "how much" from "when" — a teen might be fine with a total time limit but furious about losing their phone during specific social hours; figure out which one is actually the problem. 2. Model it yourself first. A house rule that only applies to the teenager while the parent is also on their phone constantly doesn't land, and teenagers notice the inconsistency immediately. 3. Negotiate specific no-phone windows together — meals, an hour before bed — rather than a vague "less time" goal that's hard to measure or enforce consistently. 4. Address what the phone is actually replacing — if it's genuinely the main source of their social connection, cutting it without offering something in its place usually just creates isolation, not better habits. This tends to go better as a negotiated agreement than an enforced rule — not because teenagers get to set all their own limits, but because a rule they had a hand in tends to actually survive contact with real life.