First, I'll review In the Heart of the Unknown (ItHotU) itself, then I'll review the hex flower idea and share my simulation results.

ItHotU helps you run a land-based hex crawl in a Standard Fantasy Setting. It includes an Encounter Engine and an accompanying table for generating encounter types, a Terrain Engine for generating terrain types, and a Weather Engine for generating the local weather. Each of these engines uses the hex flower idea to generate results.

The Encounter Engine covers encounter types: wandering monsters, lairs, settlements, natural obstacles, and so on. It's up to you to figure out what they mean in the current circumstances. The accompanying table lets you roll up specific creatures when needed, with modifiers according to terrain type. If your encounter says "centaur" and you can run with that, there's no other preparation required for creature encounters. You might have prep work to do, however, if you want to stat them up in advance, if you want to figure out what the centaurs are up to, or if you want to decide how they fit into the setting. You'll have some prep work if you want to customize the creature table. For the non-creature encounters, you might have some prep work on your hands if you don't want to make up a Dungeon/Feature, Small Settlement, or the like on the spot.

The Encounter Engine's river and road results help you direct the Encounter Engine toward or away from the top hex, marked "Large settlement/city/destination." There's a potential probabilty pitfall with the hex flower approach, so the road & river mechanisms help nudge play toward a particular destination. More on this below.

The Terrain Engine covers a few common terrain types, with a wildcard "special" result that has you throw in whatever other odd terrain you want. There's no indication of scale, but your overland travel scale is probably a good fit, whether the party is traveling at a rate of a few days per map hex or a few map hexes per day.

The Weather Engine helps you track weather changes. It probably needs zero prep work.

ItHotU is good as far as it goes. It gives you a pre-selected handful of creature types for a general fantasy setting, and it reduces your prep work. If your hex crawl includes waterborne travel, you'll want In the Heart of the Sea as well. If you want to customize or elaborate on any of the engines, you've got some prep work to do.

As to the hex flower approach itself, it's an elegant little tool: simple, but also versatile. It's a hexagon-based tracking tool that provides what I'd call stateful randomness. Essentially, it's a state diagram with 19 states. Your marker on each engine does a random walk around the engine's hex flower, but it can reach only certain other hexes from a given hex. This is how ItHotU stops you from going directly from flat plains to mountains in one random hop. You work your way there through other terrain first.

The interesting element is that the direction of your random walk is biased. A 2d6 roll picks the direction. I whipped up a simulation and had it run as many as 100,000 dice rolls on a hex flower to see which hexes got the most visits. My simulation assumed that you'd start at the bottom hex. It uses the wrap-around rules for when your random walk would take you off the hex flower. If you create your own hex flowers, you might want to know these results:

• The bottom hex (starting hex) and its three immediate neighbors are likely to have the most visits. Put your most common stuff there.
• The next-most frequently visited hexes will be the ones in the lower left area of the hex flower.
• The hexes getting the fewest visits will be those in the upper right area of the hex flower.
• Some of the available hex flower engines use the top hex as a destination. Given the probabilities, it's hard to get from the bottom to the top. The shortest possible journey from the bottom hex to the top hex is three hops, such as rolling 10, then 7, and then 3. It's statistically possible (but not likely) that you could make thousands of rolls and still not reach the top. In most of my simulation runs, the trip from the bottom hex to the top hex took anywhere from 4 to 40 rolls, but roughly 1 run in 4 took more than 40 rolls. Some took more than 100 rolls, but none of them reached 200. That's a lot of variability -- anywhere from 3 rolls to almost 200. If each roll is a day's journey, you're looking at a trip that could take anywhere from a few days to several months. You'll need mechanisms to help nudge things toward the top, if that's an important destination. You might even want mechanisms to stop it from happening too quickly. This is where ItHotU's road and river mechanisms can help. Other available hex flowers use other approaches for nudging the results in a desired direction.
• Only three hexes lead you to the top hex. The one to its lower left is the most likely entry point. The hex directly below the top hex is the least likely way to get there. (It takes a roll of 12 on 2d6 to move straight up on the hex flower.)

If 19 possible states and 3-200 rolls to reach the top is overkill for a situation you have in mind, you could ignore the outer ring of the hex flower and use only the seven interior hexes.