**You describe what your map should save, and it generates the EPScript for it.**
No external program. Nothing for players to install. The generated script goes
inside your map and runs on the game's own trigger system. Players get a short
code when they save and type it back in to restore progress, essentially what
SCA did, except the launcher is gone because the whole thing lives in the .scx.
THE FORMAT, IF YOU CARE
Values are packed mixed-radix into base-36 digits. EUD arithmetic is 32-bit,
a single packed integer is impossible for anything realistic, the payload is
split into groups that each fit a register, and group boundaries are chosen
a short DP to minimise wasted digits rather than a greedy fill.
Digits are scrambled by a position-dependent keystream derived from the player
name, and the whole thing carries a DJB2 checksum.
One detail worth flagging for anyone rolling their own: **the checksum modul
must be coprime to 36.** If you truncate with `hash % 36^d`, the modulus shares
every prime factor with the digit place values, and DJB2's multiplier 33 = 3
supplies more factors of 3. Some single-digit edits then change the packed value
by an exact multiple of the modulus and the checksum cannot see them at all.
That's not theoretical, I found it in my own shipped map, where 26.7% of
single-character edits were being accepted as valid. A prime modulus takes
single-character tamper detection to 100%.
Codes are capped at 15 characters, since players type them by hand. The editor
shows the length live and tells you which step to widen if you go over.
LEADERBOARD
Every generated system comes with a leaderboard on your map's page. Players
paste the same code the game gave them and it's decoded server-side.
Each project gets its own key, derived from a random value plus the project
creator IDs, so a code minted for one map can never validate against another, one map being picked apart tells nobody anything about yours. Codes are also
bound to the player's name. Submissions are rate limited per account, per IP,
and per map, with a shared daily budget of wrong guesses so a distributed
guessing attack doesn't work either.
To be straight about the limit: someone who extracts the algorithm from your
own map file can forge codes for that map. Unavoidable: the map has to cont
the algorithm to run it. That's what moderation is for.
CAVEATS
It's in beta. It works, but the format may change and leaderboards may be re
while I finish it. Free, no ads, no trackers.
I'd genuinely like this torn apart by people who know EUD. If the generated
script does something dumb, or there's a case the packer gets wrong, tell me
I'll fix it.
Site: https://www.scrmaps.com
Docs: https://www.scrmaps.com/about
Post a map, then hit "Save/Load System" on it in your dashboard.
