I've got questions, now....
First question: The situation is as detailed in the OP. Two combatants enter an arena for gladitorial combat. Both are armed with shortsword (gladius) and buckler. Both wear nothing but a loincloth.
The arena is 80' across.
If a character is going to Ready an action, then he can only move 5'* as he readies that action.
Since neither character wants to be the victim of a charge, both gladitors basically inch their way, 5' at a time, into the arena, each round declaring that they are reading an attack in case the other charges him.
Doesn't this result in a silly, Mexican Standoff situation?
Is there a way around this?
*And, this begs another question. According to the Ready Action, a character can move 5' and still ready an action. But, according to the Partial Charge rule, a character cannot take a 5' step in the same round as a Partial Charge.
Therefore, neither character can move and make a Partial Charge, even if they ready the action.
Second Question: Let's look at a simular situation, but transplant our two warriors out into a field. The gladiator with initiative says that he's readying a move action if he's charged. If he sees his opponent charging him, then he'll move behind a tree, breaking line of sight.
So, how does this play out?
1. Gladiator with nish Readies his move action.
2. His foe begins his charge.
3. The Gladiator move behind a large tree, putting an obstacle in his foe's path and breaking line of sight.
4. What happens to the foe now that he can no longer charge? How far can he move? Does he move to the tree and stop? Does he lose his action since he no longer has a line of sight to his target? If so, how far does he get when that happens?