To my knowledge the only 'handicap' you could set up for the better players is to create your own custom map and assign player location carefully. Less skilled players could have more resources nearby for example, or are surrounded by forest (but with the resources within of course). Of course, all the players would need to agree to your set up and respect the location you choose for them. This could be more entertaining for the stronger players as well, because the challenge is bigger now.
Some things to consider for the stronger players:
- More dangerous wild animals (wolfs, jaguars, etc...) and closer to the town center. This makes it risky for villagers to go too far from the town center and explore.
- Scarce resources (or even shared resources in between camps, to have them fight over it)
- no/less relics (you can even make them hard to find, like inside forests)
- disable specific buildings/research/units in the custom map (I'm not sure this still works with AOE II HD for custom maps which are then used for multiplayer)
Some things to consider for the weaker players:
- Longer peace treaty
- Enclosed area where the the stronger players can't reach them
- More starting villagers
- Starts with a small army
- No dangerous wild animals, instead supply more deer or turkeys.
- More resources and closer by
- Relics (be careful! Too many relics can seriously break the economy of your map, 2 per weak player should be enough.)
- Start with a castle next to the town center
- Start out with resource buildings next to resources (mining camp/mill)
- Lock teams when setting up the game
If you create a custom map and use it for a multiplayer game, make sure you do NOT toggle the 'All techs'. This will reset player specific settings, like disabled units.
Note that settings starting resources in the custom map won't work for multiplayer games because this will be overwritten when selecting the resources (low, medium, high).
At LAN parties I would prepare a custom map in advance and use this setup for new people. Other times I would create a custom map where we would challenge ourselves with a very powerful AI, where the AI would start with an army of 2000 (buffed) units. Teaming up against such a strong enemy could be fun with people from different skill levels, as you need to assign roles to make a strategy work properly. Usually if a skilled player thought he could go solo against the AI, he would lose, requiring a team.
Another more advanced options is to make use of triggers. In a custom map, triggers allow you to do various actions on the map or to players based on an event. For example, if a player1 comes into a certain area, you can grant player2 1000 gold. You can even place units or increase their attack and HP. In a custom map the world is yours :). Some ideas I put the practice in the past:
- A strong player crosses a certain border (think of the only bridge to cross deep water). This would grant the weaker players 2500 of each resource.
- A strong player comes into view of the town center, boost the town centers health to 20000.
- A strong player comes into view of a 'sacred monastery', kill all units in a certain area.
- A strong player comes into territory of another strong player and they become enemies (make sure to lock teams, triggers can still override this in-game)
To give it more flavour, you can have the 'world' (gaia) send out messages to all players from time to time, to warn them for certain dangers. Now the stronger players are warned and would have to think twice if their strategy would actually still work.