YOU CAN’T COME IN HERE AND ASK A QUESTION LIKE THAT… YOU’LL START A WAR! (lol, just kiding).
The simple thing to do is to give 1 free dice for anyone entering the R&D phase by purchasing at least 1 dice.
So, buy 1 and get 2, buy 2 and get 3, buy 3 and get 4…
Another idea is to have each major power choose 1 tech at the beginning of the game, each get 1 free dice during each turn, add each result from all rolls throughout the rounds until they reach 25, at which point that nation will receive the tech they choose at the start of the game.
If you want some ideas that are completely off the hook, you can go here…