As title says, I'm editing a map where some players already have aegis and I want to add another player and let them have "aegis" instant build too. Any help appreciated.

try going through the triggers in FASTEST VILLAGER DEFENCE.. its already implemented there

Yeah I reached the same conclusion and have been doing just that, looking through the triggers. Only a matter of time until I find it.

For what it's worth, that's the map I'm editing too. I wanted to make P8 more functional and unlike P1-P6 it doesn't have AEGIS built in since it was never designed to be used that way.

Well I've looked at each and every one of them now but no luck finding it. Maybe its displayed as something else. Hmmmm, annoying because I know it should only take 10 seconds once I know what I'm doing

Fast Villager Defence only makes villager build fast. There is no way to achieve "real" aegis without cheating. But here's a similar way I use:

Step 1: Download this file: [You must login to view link]

Step 2: Open your map

Step 3: Make a new trigger like this:

Name: Aegis
Starts: ON
Looping: OFF
Condition: Whatever you want, not necessary
Effect: Tribute: -1000 Build Rate from P1 to GAIA (Immediate building)
Effect: Tribute: -1000 Food Lasts from P1 to GAIA (Makes villagers get maximum food in 1 sec, BUT it only takes 1/200 of food from the source. So farms, animals, bushes etc lasts forever)
Effect: Tribute: -1000 Wood Lasts from P1 to GAIA (Makes villagers get maximum wood in 1 sec, BUT it only takes 1/200 of wood from the trees, so the trees takes a long time to dissapear)
Effect: Tribute: -1000 Stone Lasts from P1 to GAIA (Makes villagers get maximum stone in 1 sec, BUT it only takes 1/200 of stone from the stone mine, so it lasts forever)
Effect: Tribute: -1000 Gold Lasts from P1 to GAIA (Makes villagers get maximum gold in 1 sec, BUT it only takes 1/200 of gold from the goldmine, which makes the goldmines lasts forever)

Then use the "Duplicate for all players" button to make the trigger work for all players. If you only want building to be increased, only use the Build Rate

Thanks for your detailed reply BF_Basse. Unfortunately for some reason AOK Trigger Studio won't open the Fast Villager Defence map. It opens all the other ones I have (CBA, HERO etc) but crashes trying to open this one. I think this map has been edited by numerous others before me already and is a bit of a trigger nightmare. Maybe it would be better to start from scratch but I don't have that ability nor the time available.

So for now I'm putting this little project on ice. But if anyone else wants to pick it up I'm happy to share some of the ideas I had for it, mostly feedback from players to make it more balanced.

Fast Villager Defence IIRC is made with HEX-editing, which might mess up the scenario. It's also made in chinese, which might also be a cause.