The race to save Merry and Pippin, as a
Modos RPG extended conflict:
Contestants: 2. GM as the Uruk-hai, PCs as Aragorn, Legolas, and Gimli.
Rounds: as traveling 1/10th of the distance to Isengard, the orcs with a 1-round head start.
Base progress die: d8
Progress goal: orcs, 135 (average progress on a d8 x 3 actions per round x 10 rounds). Heroes, 405 (avg progress x 3 actions x 3 PCs x 10 rounds).* Orcs begin with 14 Progress, due to their head start.
Actions: 1 action per round must be Physical (movement). The remaining 2 are dictated by the story.
Play description:
The orcs have the initiative, obviously, so the GM starts. He rolls three contests for the orcs against the trials that they face on their overland march, recording the difficulties for each. Pro (success) results make Progress, Con results do not, and Tie results can be rerolled, but I would open these up to "cut scenes" for the players, with player input pushing the Ties one way or the other.
The orcs' movement contest goes against the difficulty of the terrain (and weather!), and since the PCs will be crossing the same terrain, the GM should use the same difficulty as the PCs cross that terrain. Options for their remaining two actions each round might be Physical (sneak), to try and hide their route, Mental (nature), for hunting and gathering as they go (although I think they just hungered for man-flesh), or another Physical (movement) for a forced march. Each Pro earns them a d6 of progress, reduced from d8 because they carry more gear than the PCs (including hobbits).
The PCs respond with their actions on the following turn. Each rolls a Physical (movement) contest against the difficulty of the terrain, predetermined by the GM as the orcs passed through. Their remaining options could be Mental (detect), for tracking, Mental (nature) for hunting and gathering and made more difficult by the orcs' success, Physical (movement) for forced march, which each PC would have to do if they agreed, or even Metaphysical (persuade) to motivate Gimli and his stout legs. Each Pro earns a d8 of progress. Every outcome, regardless of Pro, Con, or Tie, contributes to the narrative of that round.
The GM can give the PCs a hint of the orcs' progress if the Mental (detect) contests go well. If the orcs reach their progress goal before the PCs, Merry and Pippin become Saruman's prisoners. If the PCs reach 3 times the orc's progress (a moving bar), they catch the orcs.
This extended conflict definitely has the roll-high-to-win aspect, but it's not codified in tables, so it calls for ideas from both the GM and the PCs. PCs can get creative with their actions, like "I use my map to find a shortcut," and earn extra progress on a Pro. Or they can use character elements to gain an advantage, like "my Hero Points are for being a Dunedain, so I use my knowledge of the land for an advantage!" It's important that each action has narration or the GM/PC creates an in-story reason for each action, otherwise the process becomes a tedious roll-off instead of "remember when you decided to push on through the thunderstorm and we caught the orcs wringing out their wet loincloths!?"
*The book version of the chase, as I recall, was pretty long-winded, so 405 max progress is a fair translation of that to game rules. Because the GM sets up the conflict, she is able to decrease (or increase) the amount of max progress as desired.
