For this you need to be in adventure mode, you need spawn points, and you need to make sections.

i recommend making a couple of rooms where robots attack you with checkpoints, as a test to see if it works, and also i will try to make this simple as i can for people who are new to the level editor

For starters, i recommend making something like this (doesn't have to be good or the same as my example)

(if you already have a level that you want checkpoints to be in, skip to the 3rd part)

















You don't have to name them, but it just makes things easier to recognize
Now, add enemies, like this (They don't have to be strong enemies, sword1s or anything like that is fine)
You don't have to add Activate AI, or anything like that, either.

You should end up with something like this:











Anyway, i recommend adding numbers to the rooms so you know what checkpoint room you are in, it helps with testing
And don't forget to add enemies to the rooms, you don't have to but in my opinion it makes testing easier
Then, add a 'On Touched Enemies Dead' trigger for every room.
Like this:


























I recommend naming them (like the others), and make sure you are adding them to every room.
Then you do the door triggers (aka. make them open their doors when the on touched enemy trigger activates with the bow1s die)

Example:



































Now just do this with each room's door, except you should make the each door activate on the same room's on touched enemies dead trigger (to the left)

Note: The checkpoints will not work right now, they will work later, we will make that now

You will need sections for this, i recommend naming them for each section.

Now, create 4 sections




















It should look like that. Name them each Checkpoint (put number here) for each checkpoint, just so it isn't unorganized

now, the next step is to mark the checkpoints for the sections

it should look like this now
































For each checkpoint, mark the corresponding checkpoint with the number of the section


there is also this, mark that on so the checkpoints are visible











now, this is the slightly confusing part, i'll try to make it as simple as i can

make the FIRST (only first) section with the first checkpoint enabled on level start





































anyway, now for the other checkpoints
make each section enable after the rooms with the bow1s to the left are dead, basically just enable
the section to activate when the on touched enemies dead activates in the current room to the left

don't forget to disable on start every section besides the current one your changing the settings in for every section

then, add 3 'lose' usekey triggers in each room, the range in my opinion should probably be 8, then add a 'losechallenge' trigger found in the utility folder, mark the 3 lose usekey triggers so when you activate them you lose (on the losechallenge trigger settings) and you can see if the checkpoints worked.

now, that is done! the final part is just clicking 'upload level' and then you should see this. Add a level document (to the upper left of the adventure/challenge level publisher), and add the level your doing the test in, like this:

make sure to make the checkpoints activate on the triggers you want them too (can be done of the checkpoint settings), otherwise it will not work.




















Now, simply

hit the 'playtest' button and playtest it! it should work, if it doesn't, please tell me in the comment section. This also only works in adventure mode exclusively. It also will not work if you select 'play' in the level editor and it only works when you go to this screen and playtest it.

That's it. Now you have learned how to make checkpoints (hopefully)