The tiles add a lot to the game? I've been using a blank mat and dices, with paper to mark objects, sometimes it gets ugly, so I'm considering it...
I started DM'ing the Red Hand of Doom after seeing some pics of other people's Stone Gorge Bridge models and got inspired to try going 3D instead of just using a battlemat. I had a few dungeon tiles (from the Basic Set) but thought they were kind of limited in flexibility. After some research, I stumbled across
WorldWorks Games. They sell sets of .pdf's for printing out your own terrain. They have something like the Dungeon tiles called
DungeonLinx 2.5D which allows you to print out onto cardstock (a heavy kind of paper) all sorts of dungeon tiles. If you want to give them more heft, you can glue them down to foamcore, matboard or even the cardboard they use for cereal boxes. You spend $17 and you can print out as many copies as you'd like.
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If you want to spend a little more time and effort, they've got sets where you can print out indoor and outoor terrain that after you cut it out, you can fold it up and glue it to make fully 3D terrain, ranging from castles, to sewers, to forests (with trees that support minis for that PC who always wants to snipe from a branch), to corrupted cathedrals and even the pits of Hades.
Here's a pic of the
castle set,(and a
link to a gallery by a user who's made all sorts of castles from one $17 purchase, and he can reuse many of the elements to make them) plus something that shows all the pieces you can choose to make in as many copies as you'd like. You can also, if you have any talent with image software, change/adapt the files if you'd like.
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A corrupted church...
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The outdoor terrain...
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Unlike the dungeon tiles, everything's made in a very modular fashion, so you can easily use and reuse terrain elements to make all sorts of encounters. In my RHoD game, I used some of the buildings I made for Vraath Keep as buildings for a goblin raid on a town to shops to parts of the Rhest Town Hall. These pics show a couple of my builds which shows how someone with little talent can actually make something that looks decent, even if I was skimping by gluing bases to cardboard from amazon packing boxes and made the mistake of printing on two different printers (that's why one of the walls is a different color from the others.
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My Vraath keep
Rhest Town Hall
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The company's a small company, but they really focus on high quality stuff. If you're willing to spend $$ on buying multiple copies of dungeon tiles, you might want to take a look at some of their stuff and see if it would serve your purposes better.