Can you play PUBG offline, and what actually works without a connection
The question comes up before every long bus trip and every flight: can the battle royale be played offline? The short answer is no, and it is worth understanding why, because the reason rules out most of the workarounds people trade in comment threads.
The match is not on your phone
A battle royale match is a shared simulation. Every player's position, every shot and every shrinking circle is arbitrated on the publisher's servers, not on the handset in your hand. Your phone draws the result and sends your inputs; it does not own the game state. That is also what keeps the game playable competitively — if the handset were the authority, changing the outcome would be as easy as editing a file.
So there is nothing to disconnect from. Without a connection there is no match to join, no lobby to sit in, and in most cases no way past the login screen, because the account check happens before the menu appears. Training grounds and practice ranges feel like single-player content, but they are served the same way, and they go dark with the rest of it.
The workarounds circulated online do not change this. An emulator on a laptop still needs the server. A modified client claiming offline play is either a different game wearing the same name or an invitation to lose the account, and account bans for modified clients are permanent. Downloading the game over a hotel connection means the assets are local; the match still is not.
What you can do without a connection
Plan for a different kind of play rather than the same play without the internet. The offline shelf on both app stores is deep: racing games, shooters with campaign modes, strategy games, roguelikes and puzzle games that never ask for a login. The useful trick is to install and launch each one at home, because plenty of nominally offline titles fetch an update or an advert on first run and refuse to start without it. A game that has already been launched once, with its data downloaded, is the one that will work at altitude.
If the aim is to keep playing the battle royale on a weak connection rather than none at all, a few things genuinely help. Lower the graphics preset, which cuts the work the phone does and with it the heat that throttles performance. Turn off background app refresh and automatic updates so the little bandwidth you have goes to the match. Use the lighter build of the game if the publisher offers one for low-end devices; it downloads less and streams less. And accept that a shared cellular connection in a moving vehicle will produce rubber-banding no setting can fix.
The honest answer to give a friend
Online-only is a design decision, not an oversight, and it is not going to be patched away. If a game needs to be playable on a plane, it has to be a game built to run on the device alone — and the good news is that the single-player library on a modern phone is better than it has ever been. Keep two or three of those installed and tested, and the question stops mattering.