Drax wrote:There's a way around it I guess; depends how the mapbook handles like "floor 99".
won't work... you will see that you never were there because the map is empty.
but on the other side, it don't think you need to keep it secret... because for being intersting, the time travel must be over o long period of time (years at least, so the look of the walls will be different, and more importantly some parts of the tunnels will be slighlty different (for example a corrider won't be collapsed in the past, or a pit will be fulled or a porticulis will get rusted in the future... only if you do some manipulation in the past, like opening a water tap...)
If you choose to make it obvious (better looking wall, runes about flow of time, map named 'past'), it's really easy and is basically two differents levels with almost the same layout.
the only thing i'm not sure is if you can 'skip' levels with stairs (making the player going from level 4 to 6 with one stair)
it not, there is still options, the simpliest one being making a small corridor of one/two tiles between the two stairs in level 5.
or may be, just using teleporters if you can choose the level of destination
another 'fun' enigma with time travel : killing 2 baby ogres in the past will clear a room full of fully grown ogres.